diff --git a/src/Api/ApigeeX/Normalizer/AcceptedRatePlanNormalizer.php b/src/Api/ApigeeX/Normalizer/AcceptedRatePlanNormalizer.php
index e84a51c4..abe09791 100755
--- a/src/Api/ApigeeX/Normalizer/AcceptedRatePlanNormalizer.php
+++ b/src/Api/ApigeeX/Normalizer/AcceptedRatePlanNormalizer.php
@@ -32,7 +32,7 @@ class AcceptedRatePlanNormalizer extends EntityNormalizer
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var AcceptedRatePlanInterface $object */
         /** @var object $normalized */
@@ -44,7 +44,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof AcceptedRatePlanInterface;
     }
diff --git a/src/Api/ApigeeX/Normalizer/ApiProductNormalizer.php b/src/Api/ApigeeX/Normalizer/ApiProductNormalizer.php
index 05ab9e6c..4ab87a1d 100755
--- a/src/Api/ApigeeX/Normalizer/ApiProductNormalizer.php
+++ b/src/Api/ApigeeX/Normalizer/ApiProductNormalizer.php
@@ -48,7 +48,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         $normalized = parent::normalize($object, $format, $context);
 
@@ -58,7 +58,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof ApiProductInterface;
     }
diff --git a/src/Api/ApigeeX/Normalizer/AppGroupMembershipNormalizer.php b/src/Api/ApigeeX/Normalizer/AppGroupMembershipNormalizer.php
index f0fba9e9..280a358a 100644
--- a/src/Api/ApigeeX/Normalizer/AppGroupMembershipNormalizer.php
+++ b/src/Api/ApigeeX/Normalizer/AppGroupMembershipNormalizer.php
@@ -29,7 +29,7 @@ class AppGroupMembershipNormalizer implements NormalizerInterface
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         $normalized = [];
 
@@ -44,8 +44,18 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof AppGroupMembership;
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getSupportedTypes(?string $format): array
+    {
+        return [
+            AppGroupMembership::class => true,
+        ];
+    }
 }
diff --git a/src/Api/ApigeeX/Normalizer/AppNormalizer.php b/src/Api/ApigeeX/Normalizer/AppNormalizer.php
index 3f7b3564..8eb0b9e1 100644
--- a/src/Api/ApigeeX/Normalizer/AppNormalizer.php
+++ b/src/Api/ApigeeX/Normalizer/AppNormalizer.php
@@ -30,7 +30,7 @@ class AppNormalizer extends ObjectNormalizer implements NormalizerInterface
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof AppInterface;
     }
@@ -41,7 +41,7 @@ public function supportsNormalization($data, $format = null)
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
diff --git a/src/Api/ApigeeX/Normalizer/BillingTypeNormalizer.php b/src/Api/ApigeeX/Normalizer/BillingTypeNormalizer.php
index a7e73b0d..25a35d4f 100644
--- a/src/Api/ApigeeX/Normalizer/BillingTypeNormalizer.php
+++ b/src/Api/ApigeeX/Normalizer/BillingTypeNormalizer.php
@@ -29,7 +29,7 @@ class BillingTypeNormalizer extends EntityNormalizer
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var BillingTypeInterface $object */
         /** @var object $normalized */
@@ -41,7 +41,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof BillingTypeInterface;
     }
diff --git a/src/Api/ApigeeX/Normalizer/PrepaidBalanceNormalizer.php b/src/Api/ApigeeX/Normalizer/PrepaidBalanceNormalizer.php
index 72f9bb10..6a9ee05e 100755
--- a/src/Api/ApigeeX/Normalizer/PrepaidBalanceNormalizer.php
+++ b/src/Api/ApigeeX/Normalizer/PrepaidBalanceNormalizer.php
@@ -45,7 +45,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
     /**
      * {@inheritDoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof PrepaidBalanceInterface;
     }
diff --git a/src/Api/ApigeeX/Normalizer/RatePlanNormalizer.php b/src/Api/ApigeeX/Normalizer/RatePlanNormalizer.php
index c8a45393..b78d8268 100755
--- a/src/Api/ApigeeX/Normalizer/RatePlanNormalizer.php
+++ b/src/Api/ApigeeX/Normalizer/RatePlanNormalizer.php
@@ -52,7 +52,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -70,7 +70,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof RatePlanInterface;
     }
diff --git a/src/Api/ApigeeX/Normalizer/RatePlanNormalizerFactory.php b/src/Api/ApigeeX/Normalizer/RatePlanNormalizerFactory.php
index 3debb38a..70730221 100755
--- a/src/Api/ApigeeX/Normalizer/RatePlanNormalizerFactory.php
+++ b/src/Api/ApigeeX/Normalizer/RatePlanNormalizerFactory.php
@@ -56,7 +56,7 @@ public function __construct(array $normalizers = [])
      * @psalm-suppress InvalidNullableReturnType - There are going to be at
      * least one normalizer always that can normalize data here.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         foreach ($this->normalizers as $normalizer) {
             // Return the result from the first denormalizer that can
@@ -70,7 +70,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         foreach ($this->normalizers as $denormalizer) {
             if ($denormalizer->supportsNormalization($data, $format)) {
diff --git a/src/Api/ApigeeX/Normalizer/RatePlanRateNormalizer.php b/src/Api/ApigeeX/Normalizer/RatePlanRateNormalizer.php
index e2626f1c..d1214aa6 100755
--- a/src/Api/ApigeeX/Normalizer/RatePlanRateNormalizer.php
+++ b/src/Api/ApigeeX/Normalizer/RatePlanRateNormalizer.php
@@ -30,7 +30,7 @@ class RatePlanRateNormalizer extends ObjectNormalizer
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -46,7 +46,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof RatePlanRate;
     }
diff --git a/src/Api/ApigeeX/Normalizer/StandardRatePlanNormalizer.php b/src/Api/ApigeeX/Normalizer/StandardRatePlanNormalizer.php
index dda8754f..b0874e41 100755
--- a/src/Api/ApigeeX/Normalizer/StandardRatePlanNormalizer.php
+++ b/src/Api/ApigeeX/Normalizer/StandardRatePlanNormalizer.php
@@ -29,7 +29,7 @@ class StandardRatePlanNormalizer extends RatePlanNormalizer
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -41,7 +41,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof StandardRatePlanInterface;
     }
diff --git a/src/Api/Management/Normalizer/AppCredentialNormalizer.php b/src/Api/Management/Normalizer/AppCredentialNormalizer.php
index 0903c413..21d88a4d 100644
--- a/src/Api/Management/Normalizer/AppCredentialNormalizer.php
+++ b/src/Api/Management/Normalizer/AppCredentialNormalizer.php
@@ -30,7 +30,7 @@ class AppCredentialNormalizer extends ObjectNormalizer implements NormalizerInte
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof AppCredentialInterface;
     }
@@ -41,7 +41,7 @@ public function supportsNormalization($data, $format = null)
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
diff --git a/src/Api/Management/Normalizer/AppNormalizer.php b/src/Api/Management/Normalizer/AppNormalizer.php
index 5010f277..e94276cb 100644
--- a/src/Api/Management/Normalizer/AppNormalizer.php
+++ b/src/Api/Management/Normalizer/AppNormalizer.php
@@ -30,7 +30,7 @@ class AppNormalizer extends ObjectNormalizer implements NormalizerInterface
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof AppInterface;
     }
@@ -41,7 +41,7 @@ public function supportsNormalization($data, $format = null)
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
diff --git a/src/Api/Management/Normalizer/CompanyMembershipNormalizer.php b/src/Api/Management/Normalizer/CompanyMembershipNormalizer.php
index 68065c92..8e36875d 100644
--- a/src/Api/Management/Normalizer/CompanyMembershipNormalizer.php
+++ b/src/Api/Management/Normalizer/CompanyMembershipNormalizer.php
@@ -19,7 +19,6 @@
 namespace Apigee\Edge\Api\Management\Normalizer;
 
 use Apigee\Edge\Api\Management\Structure\CompanyMembership;
-use ArrayObject;
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 
 class CompanyMembershipNormalizer implements NormalizerInterface
@@ -30,7 +29,7 @@ class CompanyMembershipNormalizer implements NormalizerInterface
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         $normalized = [
             'developer' => [],
@@ -42,13 +41,13 @@ public function normalize($object, $format = null, array $context = [])
 
         // convert to ArrayObject as symfony normalizer throws error for std object.
         // set ARRAY_AS_PROPS flag as we need entries to be accessed as properties.
-        return new ArrayObject($normalized, ArrayObject::ARRAY_AS_PROPS);
+        return new \ArrayObject($normalized, \ArrayObject::ARRAY_AS_PROPS);
     }
 
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof CompanyMembership;
     }
diff --git a/src/Api/Management/Query/StatsQueryNormalizer.php b/src/Api/Management/Query/StatsQueryNormalizer.php
index 0bff438a..dc50bcd6 100644
--- a/src/Api/Management/Query/StatsQueryNormalizer.php
+++ b/src/Api/Management/Query/StatsQueryNormalizer.php
@@ -52,7 +52,7 @@ public function __construct()
     /**
      * {@inheritdoc}
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var StatsQueryInterface $object */
         // Transform the object to JSON and back to an array to keep boolean values as boolean.
@@ -92,7 +92,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof StatsQuery;
     }
diff --git a/src/Api/Monetization/Normalizer/AcceptedRatePlanNormalizer.php b/src/Api/Monetization/Normalizer/AcceptedRatePlanNormalizer.php
index 85242c3b..170a79e4 100644
--- a/src/Api/Monetization/Normalizer/AcceptedRatePlanNormalizer.php
+++ b/src/Api/Monetization/Normalizer/AcceptedRatePlanNormalizer.php
@@ -31,7 +31,7 @@ class AcceptedRatePlanNormalizer extends EntityNormalizer
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var AcceptedRatePlanInterface $object */
         /** @var object $normalized */
@@ -44,7 +44,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof AcceptedRatePlanInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/AddressNormalizer.php b/src/Api/Monetization/Normalizer/AddressNormalizer.php
index 952074d7..b2f94129 100644
--- a/src/Api/Monetization/Normalizer/AddressNormalizer.php
+++ b/src/Api/Monetization/Normalizer/AddressNormalizer.php
@@ -45,7 +45,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof Address;
     }
diff --git a/src/Api/Monetization/Normalizer/ApiPackageNormalizer.php b/src/Api/Monetization/Normalizer/ApiPackageNormalizer.php
index 1be6dfb4..022922ee 100644
--- a/src/Api/Monetization/Normalizer/ApiPackageNormalizer.php
+++ b/src/Api/Monetization/Normalizer/ApiPackageNormalizer.php
@@ -47,7 +47,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         $normalized = (array) parent::normalize($object, $format, $context);
 
@@ -63,7 +63,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof ApiPackageInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/BalanceNormalizer.php b/src/Api/Monetization/Normalizer/BalanceNormalizer.php
index caf718ba..e467b88b 100644
--- a/src/Api/Monetization/Normalizer/BalanceNormalizer.php
+++ b/src/Api/Monetization/Normalizer/BalanceNormalizer.php
@@ -44,7 +44,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof BalanceInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/CompanyAcceptedRatePlanNormalizer.php b/src/Api/Monetization/Normalizer/CompanyAcceptedRatePlanNormalizer.php
index c1331400..98341571 100644
--- a/src/Api/Monetization/Normalizer/CompanyAcceptedRatePlanNormalizer.php
+++ b/src/Api/Monetization/Normalizer/CompanyAcceptedRatePlanNormalizer.php
@@ -44,7 +44,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof CompanyAcceptedRatePlanInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/CompanyPaymentTransactionNormalizer.php b/src/Api/Monetization/Normalizer/CompanyPaymentTransactionNormalizer.php
index f86a78d6..1a3f9577 100644
--- a/src/Api/Monetization/Normalizer/CompanyPaymentTransactionNormalizer.php
+++ b/src/Api/Monetization/Normalizer/CompanyPaymentTransactionNormalizer.php
@@ -47,7 +47,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -59,7 +59,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof CompanyPaymentTransaction;
     }
diff --git a/src/Api/Monetization/Normalizer/CompanyRatePlanNormalizer.php b/src/Api/Monetization/Normalizer/CompanyRatePlanNormalizer.php
index cfc5eaab..2851b632 100644
--- a/src/Api/Monetization/Normalizer/CompanyRatePlanNormalizer.php
+++ b/src/Api/Monetization/Normalizer/CompanyRatePlanNormalizer.php
@@ -44,7 +44,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof CompanyRatePlanInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/CompanyReportDefinitionNormalizer.php b/src/Api/Monetization/Normalizer/CompanyReportDefinitionNormalizer.php
index 3c155635..22974aea 100644
--- a/src/Api/Monetization/Normalizer/CompanyReportDefinitionNormalizer.php
+++ b/src/Api/Monetization/Normalizer/CompanyReportDefinitionNormalizer.php
@@ -44,7 +44,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof CompanyReportDefinitionInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/DateTimeZoneNormalizer.php b/src/Api/Monetization/Normalizer/DateTimeZoneNormalizer.php
index 8eba9f35..38cef829 100644
--- a/src/Api/Monetization/Normalizer/DateTimeZoneNormalizer.php
+++ b/src/Api/Monetization/Normalizer/DateTimeZoneNormalizer.php
@@ -26,7 +26,7 @@ class DateTimeZoneNormalizer implements NormalizerInterface
     /**
      * {@inheritdoc}
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         return $object->getName();
     }
@@ -34,7 +34,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof DateTimeZone;
     }
diff --git a/src/Api/Monetization/Normalizer/DeveloperCategoryRatePlanNormalizer.php b/src/Api/Monetization/Normalizer/DeveloperCategoryRatePlanNormalizer.php
index c56ffd0d..9f8788a6 100644
--- a/src/Api/Monetization/Normalizer/DeveloperCategoryRatePlanNormalizer.php
+++ b/src/Api/Monetization/Normalizer/DeveloperCategoryRatePlanNormalizer.php
@@ -29,7 +29,7 @@ class DeveloperCategoryRatePlanNormalizer extends RatePlanNormalizer
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -41,7 +41,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof DeveloperCategoryRatePlanInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/DeveloperPaymentTransactionNormalizer.php b/src/Api/Monetization/Normalizer/DeveloperPaymentTransactionNormalizer.php
index 341a715a..139c6e38 100644
--- a/src/Api/Monetization/Normalizer/DeveloperPaymentTransactionNormalizer.php
+++ b/src/Api/Monetization/Normalizer/DeveloperPaymentTransactionNormalizer.php
@@ -28,7 +28,7 @@ class DeveloperPaymentTransactionNormalizer extends PaymentTransactionNormalizer
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -40,7 +40,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof DeveloperPaymentTransaction;
     }
diff --git a/src/Api/Monetization/Normalizer/DeveloperRatePlanNormalizer.php b/src/Api/Monetization/Normalizer/DeveloperRatePlanNormalizer.php
index 9c8f0ccb..1b9a3f85 100644
--- a/src/Api/Monetization/Normalizer/DeveloperRatePlanNormalizer.php
+++ b/src/Api/Monetization/Normalizer/DeveloperRatePlanNormalizer.php
@@ -25,7 +25,7 @@ class DeveloperRatePlanNormalizer extends LegalEntityRatePlanNormalizer
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof DeveloperRatePlanInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/DeveloperReportDefinitionNormalizer.php b/src/Api/Monetization/Normalizer/DeveloperReportDefinitionNormalizer.php
index 7a5739d5..9e804d59 100644
--- a/src/Api/Monetization/Normalizer/DeveloperReportDefinitionNormalizer.php
+++ b/src/Api/Monetization/Normalizer/DeveloperReportDefinitionNormalizer.php
@@ -25,7 +25,7 @@ class DeveloperReportDefinitionNormalizer extends LegalEntityReportDefinitionNor
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof DeveloperReportDefinitionInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/EntityNormalizer.php b/src/Api/Monetization/Normalizer/EntityNormalizer.php
index cbae260c..0f7a8175 100644
--- a/src/Api/Monetization/Normalizer/EntityNormalizer.php
+++ b/src/Api/Monetization/Normalizer/EntityNormalizer.php
@@ -63,7 +63,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
      * @psalm-suppress InvalidReturnType stdClass is also an object.
      * @psalm-suppress InvalidPropertyFetch.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         $normalized = (array) parent::normalize($object, $format, $context);
 
diff --git a/src/Api/Monetization/Normalizer/LegalEntityNormalizer.php b/src/Api/Monetization/Normalizer/LegalEntityNormalizer.php
index 3259c4e6..70fb383c 100644
--- a/src/Api/Monetization/Normalizer/LegalEntityNormalizer.php
+++ b/src/Api/Monetization/Normalizer/LegalEntityNormalizer.php
@@ -49,7 +49,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -66,7 +66,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof LegalEntityInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/LegalEntityRatePlanNormalizer.php b/src/Api/Monetization/Normalizer/LegalEntityRatePlanNormalizer.php
index 50c51842..bae1a783 100644
--- a/src/Api/Monetization/Normalizer/LegalEntityRatePlanNormalizer.php
+++ b/src/Api/Monetization/Normalizer/LegalEntityRatePlanNormalizer.php
@@ -28,7 +28,7 @@ abstract class LegalEntityRatePlanNormalizer extends RatePlanNormalizer
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
diff --git a/src/Api/Monetization/Normalizer/LegalEntityReportDefinitionNormalizer.php b/src/Api/Monetization/Normalizer/LegalEntityReportDefinitionNormalizer.php
index 54f1bb9e..bcd7e489 100644
--- a/src/Api/Monetization/Normalizer/LegalEntityReportDefinitionNormalizer.php
+++ b/src/Api/Monetization/Normalizer/LegalEntityReportDefinitionNormalizer.php
@@ -18,6 +18,7 @@
 
 namespace Apigee\Edge\Api\Monetization\Normalizer;
 
+
 abstract class LegalEntityReportDefinitionNormalizer extends ReportDefinitionNormalizer
 {
     /**
@@ -26,7 +27,7 @@ abstract class LegalEntityReportDefinitionNormalizer extends ReportDefinitionNor
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
diff --git a/src/Api/Monetization/Normalizer/OrganizationProfileNormalizer.php b/src/Api/Monetization/Normalizer/OrganizationProfileNormalizer.php
index fdde13ac..fc4d9448 100644
--- a/src/Api/Monetization/Normalizer/OrganizationProfileNormalizer.php
+++ b/src/Api/Monetization/Normalizer/OrganizationProfileNormalizer.php
@@ -44,7 +44,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof OrganizationProfileInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/PaymentTransactionNormalizer.php b/src/Api/Monetization/Normalizer/PaymentTransactionNormalizer.php
index 065f868d..0c0e9826 100644
--- a/src/Api/Monetization/Normalizer/PaymentTransactionNormalizer.php
+++ b/src/Api/Monetization/Normalizer/PaymentTransactionNormalizer.php
@@ -45,7 +45,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof PaymentTransaction;
     }
diff --git a/src/Api/Monetization/Normalizer/PrepaidBalanceNormalizer.php b/src/Api/Monetization/Normalizer/PrepaidBalanceNormalizer.php
index 0cbc4557..7cb321e9 100644
--- a/src/Api/Monetization/Normalizer/PrepaidBalanceNormalizer.php
+++ b/src/Api/Monetization/Normalizer/PrepaidBalanceNormalizer.php
@@ -44,7 +44,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof PrepaidBalanceInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/RatePlanNormalizer.php b/src/Api/Monetization/Normalizer/RatePlanNormalizer.php
index 95b008f4..e4d8a78c 100644
--- a/src/Api/Monetization/Normalizer/RatePlanNormalizer.php
+++ b/src/Api/Monetization/Normalizer/RatePlanNormalizer.php
@@ -51,7 +51,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -75,7 +75,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof RatePlanInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/RatePlanNormalizerFactory.php b/src/Api/Monetization/Normalizer/RatePlanNormalizerFactory.php
index 0af7aff6..b62fc8bb 100644
--- a/src/Api/Monetization/Normalizer/RatePlanNormalizerFactory.php
+++ b/src/Api/Monetization/Normalizer/RatePlanNormalizerFactory.php
@@ -53,7 +53,7 @@ public function __construct(array $normalizers = [])
      * @psalm-suppress InvalidNullableReturnType - There are going to be at
      * least one normalizer always that can normalize data here.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         foreach ($this->normalizers as $normalizer) {
             // Return the result from the first denormalizer that can
@@ -67,7 +67,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         foreach ($this->normalizers as $denormalizer) {
             if ($denormalizer->supportsNormalization($data, $format)) {
diff --git a/src/Api/Monetization/Normalizer/RatePlanRateNormalizer.php b/src/Api/Monetization/Normalizer/RatePlanRateNormalizer.php
index b8f47969..ced20de3 100644
--- a/src/Api/Monetization/Normalizer/RatePlanRateNormalizer.php
+++ b/src/Api/Monetization/Normalizer/RatePlanRateNormalizer.php
@@ -30,7 +30,7 @@ class RatePlanRateNormalizer extends ObjectNormalizer
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -46,7 +46,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof RatePlanRate;
     }
diff --git a/src/Api/Monetization/Normalizer/ReportCriteriaNormalizer.php b/src/Api/Monetization/Normalizer/ReportCriteriaNormalizer.php
index ff81fbd4..7776ce09 100644
--- a/src/Api/Monetization/Normalizer/ReportCriteriaNormalizer.php
+++ b/src/Api/Monetization/Normalizer/ReportCriteriaNormalizer.php
@@ -59,7 +59,7 @@ public function __construct(string $organization, ?ClassMetadataFactoryInterface
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -95,7 +95,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof AbstractCriteria;
     }
diff --git a/src/Api/Monetization/Normalizer/ReportDefinitionNormalizer.php b/src/Api/Monetization/Normalizer/ReportDefinitionNormalizer.php
index 2cf26536..f49affe1 100644
--- a/src/Api/Monetization/Normalizer/ReportDefinitionNormalizer.php
+++ b/src/Api/Monetization/Normalizer/ReportDefinitionNormalizer.php
@@ -50,7 +50,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var ReportDefinitionInterface $object */
         /** @var object $normalized */
@@ -67,7 +67,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof ReportDefinitionInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/StandardRatePlanNormalizer.php b/src/Api/Monetization/Normalizer/StandardRatePlanNormalizer.php
index 3914a8cf..a6f17a58 100644
--- a/src/Api/Monetization/Normalizer/StandardRatePlanNormalizer.php
+++ b/src/Api/Monetization/Normalizer/StandardRatePlanNormalizer.php
@@ -29,7 +29,7 @@ class StandardRatePlanNormalizer extends RatePlanNormalizer
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -41,7 +41,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof StandardRatePlanInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/SupportedCurrencyNormalizer.php b/src/Api/Monetization/Normalizer/SupportedCurrencyNormalizer.php
index 13e36e4f..d2239970 100644
--- a/src/Api/Monetization/Normalizer/SupportedCurrencyNormalizer.php
+++ b/src/Api/Monetization/Normalizer/SupportedCurrencyNormalizer.php
@@ -44,7 +44,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof SupportedCurrencyInterface;
     }
diff --git a/src/Api/Monetization/Normalizer/TermsAndConditionsNormalizer.php b/src/Api/Monetization/Normalizer/TermsAndConditionsNormalizer.php
index 80d5c8d1..70117e1f 100644
--- a/src/Api/Monetization/Normalizer/TermsAndConditionsNormalizer.php
+++ b/src/Api/Monetization/Normalizer/TermsAndConditionsNormalizer.php
@@ -51,7 +51,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /** @var object $normalized */
         $normalized = parent::normalize($object, $format, $context);
@@ -72,7 +72,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof TermsAndConditionsInterface;
     }
diff --git a/src/Normalizer/CredentialProductNormalizer.php b/src/Normalizer/CredentialProductNormalizer.php
index 7a1b1adb..3e43bf23 100644
--- a/src/Normalizer/CredentialProductNormalizer.php
+++ b/src/Normalizer/CredentialProductNormalizer.php
@@ -19,7 +19,6 @@
 namespace Apigee\Edge\Normalizer;
 
 use Apigee\Edge\Structure\CredentialProductInterface;
-use ArrayObject;
 use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
 
 /**
@@ -33,7 +32,7 @@ class CredentialProductNormalizer implements NormalizerInterface
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /* @var \Apigee\Edge\Structure\CredentialProductInterface $object */
         $asObject = [
@@ -43,13 +42,13 @@ public function normalize($object, $format = null, array $context = [])
 
         // Need to convert to ArrayObject as symfony normalizer throws error for std object.
         // Need to set ARRAY_AS_PROPS flag as we need Entries to be accessed as properties.
-        return new ArrayObject($asObject, ArrayObject::ARRAY_AS_PROPS);
+        return new \ArrayObject($asObject, \ArrayObject::ARRAY_AS_PROPS);
     }
 
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof CredentialProductInterface;
     }
diff --git a/src/Normalizer/EdgeDateNormalizer.php b/src/Normalizer/EdgeDateNormalizer.php
index 77025207..f63d7af6 100644
--- a/src/Normalizer/EdgeDateNormalizer.php
+++ b/src/Normalizer/EdgeDateNormalizer.php
@@ -26,7 +26,7 @@ class EdgeDateNormalizer implements NormalizerInterface
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof DateTimeInterface;
     }
@@ -34,7 +34,7 @@ public function supportsNormalization($data, $format = null)
     /**
      * {@inheritdoc}
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         /* @var \DateTimeInterface $object */
         return $object->getTimestamp() * 1000;
diff --git a/src/Normalizer/KeyValueMapNormalizer.php b/src/Normalizer/KeyValueMapNormalizer.php
index 998c0427..1f7e0e5b 100644
--- a/src/Normalizer/KeyValueMapNormalizer.php
+++ b/src/Normalizer/KeyValueMapNormalizer.php
@@ -29,7 +29,7 @@ class KeyValueMapNormalizer implements NormalizerInterface
     /**
      * {@inheritdoc}
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         $return = [];
         foreach ($object->values() as $key => $value) {
@@ -42,7 +42,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof KeyValueMapInterface;
     }
diff --git a/src/Normalizer/ObjectNormalizer.php b/src/Normalizer/ObjectNormalizer.php
index 644e9d21..666690f6 100644
--- a/src/Normalizer/ObjectNormalizer.php
+++ b/src/Normalizer/ObjectNormalizer.php
@@ -19,7 +19,6 @@
 namespace Apigee\Edge\Normalizer;
 
 use Apigee\Edge\PropertyAccess\PropertyAccessorDecorator;
-use ArrayObject;
 use Symfony\Component\PropertyAccess\PropertyAccess;
 use Symfony\Component\PropertyAccess\PropertyAccessorInterface;
 use Symfony\Component\PropertyInfo\Extractor\PhpDocExtractor;
@@ -94,7 +93,7 @@ public function __construct(?ClassMetadataFactoryInterface $classMetadataFactory
      * @psalm-suppress PossiblyInvalidArgument First argument of array_filter is always an array.
      * @psalm-suppress PossiblyNullArgument First argument of array_filter is always an array.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         $asArray = $this->objectNormalizer->normalize($object, $this->format, $context);
         // Exclude null values from the output, even if PATCH is not supported on Apigee Edge
@@ -110,7 +109,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         // Enforce the only supported format if format is null.
         $format = $format ?? $this->format;
@@ -130,10 +129,10 @@ public function setSerializer(SerializerInterface $serializer): void
     /**
      * {@inheritDoc}
      */
-    public function convertToArrayObject($normalized, $array_as_props = ArrayObject::ARRAY_AS_PROPS)
+    public function convertToArrayObject($normalized, $array_as_props = \ArrayObject::ARRAY_AS_PROPS)
     {
         // default set ARRAY_AS_PROPS flag as we need entries to be accessed as properties.
-        return new ArrayObject($normalized, $array_as_props);
+        return new \ArrayObject($normalized, $array_as_props);
     }
 
     /**
diff --git a/src/Normalizer/PropertiesPropertyNormalizer.php b/src/Normalizer/PropertiesPropertyNormalizer.php
index 7818c637..eb66bbd9 100644
--- a/src/Normalizer/PropertiesPropertyNormalizer.php
+++ b/src/Normalizer/PropertiesPropertyNormalizer.php
@@ -19,7 +19,6 @@
 namespace Apigee\Edge\Normalizer;
 
 use Apigee\Edge\Structure\PropertiesProperty;
-use ArrayObject;
 
 /**
  * Class PropertiesPropertyNormalizer.
@@ -34,7 +33,7 @@ class PropertiesPropertyNormalizer extends KeyValueMapNormalizer
      * @psalm-suppress InvalidReturnType Returning an object here is required
      * for creating a valid Apigee Edge request.
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         $return = [
             'property' => parent::normalize($object, $format, $context),
@@ -42,13 +41,13 @@ public function normalize($object, $format = null, array $context = [])
 
         // convert to ArrayObject as symfony normalizer throws error for std object.
         // set ARRAY_AS_PROPS flag as we need entries to be accessed as properties.
-        return new ArrayObject($return, ArrayObject::ARRAY_AS_PROPS);
+        return new \ArrayObject($return, \ArrayObject::ARRAY_AS_PROPS);
     }
 
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $data instanceof PropertiesProperty;
     }
diff --git a/src/Serializer/EntitySerializer.php b/src/Serializer/EntitySerializer.php
index cf151fa4..d78d6c84 100755
--- a/src/Serializer/EntitySerializer.php
+++ b/src/Serializer/EntitySerializer.php
@@ -90,7 +90,7 @@ public function supportsDenormalization($data, $type, $format = null): bool
     /**
      * {@inheritdoc}
      */
-    public function normalize($object, $format = null, array $context = [])
+    public function normalize($object, $format = null, array $context = []): array|string|int|float|bool|\ArrayObject|null
     {
         return $this->serializer->normalize($object, $format, $context);
     }
@@ -98,7 +98,7 @@ public function normalize($object, $format = null, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsNormalization($data, $format = null)
+    public function supportsNormalization($data, $format = null): bool
     {
         return $this->format === $format && $this->serializer->supportsNormalization($data, $format);
     }
@@ -199,7 +199,7 @@ public function decode($data, $format, array $context = [])
     /**
      * {@inheritdoc}
      */
-    public function supportsDecoding($format)
+    public function supportsDecoding($format): bool
     {
         return $this->format === $format && $this->serializer->supportsDecoding($format);
     }