diff --git a/tests/test_core_with_model.py b/tests/test_core_with_model.py
index a80d862..5a5a5e0 100644
--- a/tests/test_core_with_model.py
+++ b/tests/test_core_with_model.py
@@ -45,6 +45,7 @@ def test_sample_initial_particles(test_model):
         assert particle.r == (1.0, 2.0, 3.0)
     assert len(particles) == 43
 
+
 def test_energy_plot_with_bins(test_model):
     plot = test_model.plot_source_energy(
         n_samples=10,