Add javadocs

fluent-kafka-streams-tests/src/main/java/com/bakdata/fluent_kafka_streams_tests/BaseOutput.java

@@ -116,6 +116,15 @@ public TestOutput<K, V> asStream() {
         return new StreamOutput<>(this.testDriver, this.topic, this.keySerde, this.valueSerde);
     }
 
+    /**
+     * Convert the output to a {@link java.util.List}. In case the current instance of this class is a
+     * {@link StreamOutput}, the output will be converted to List with {@link org.apache.kafka.streams.kstream.KStream}
+     * semantics (each key multiple times). In case the current instance of this class is a {@link TableOutput}, the
+     * output will be converted to List with {@link org.apache.kafka.streams.kstream.KTable} semantics (each key only
+     * once).
+     *
+     * @return A {@link java.util.List} representing the output
+     */
     @Override
     public List<ProducerRecord<K, V>> toList() {
         final List<ProducerRecord<K, V>> list = new ArrayList<>();

fluent-kafka-streams-tests/src/main/java/com/bakdata/fluent_kafka_streams_tests/TestOutput.java

@@ -145,10 +145,16 @@ default <VR> TestOutput<K, VR> withValueType(final Class<VR> valueType) {
      * <p>This is the default, there should usually be no need to call this method.</p>
      * <p>Note: once the first value of the stream has been read or the iterator has be called, you cannot switch
      * between the output types any more.</p>
+     *
      * @return Current output with {@link org.apache.kafka.streams.kstream.KStream} semantics
      */
     TestOutput<K, V> asStream();
 
+    /**
+     * Convert the output to a {@link java.util.List}.
+     *
+     * @return A {@link java.util.List} representing the output
+     */
     List<ProducerRecord<K, V>> toList();
 }