add comments

tests/models/gemma2/test_modeling_gemma2.py

@@ -140,6 +140,7 @@ def test_generate_with_static_cache(self):
     def test_generate_from_inputs_embeds_with_static_cache(self):
         pass
 
+    # overwrite because HybridCache has fixed length for key/values
     def _check_attentions_for_generate(
         self, batch_size, attentions, min_length, max_length, config, use_cache=False, num_beam_groups=1
     ):
@@ -151,7 +152,7 @@ def _check_attentions_for_generate(
 
         for idx, iter_attentions in enumerate(attentions):
             tgt_len = min_length + idx if not use_cache else 1
-            src_len = min_length + idx if not use_cache else max_length  # HybridCache has fixed length for key/values
+            src_len = min_length + idx if not use_cache else max_length
 
             expected_shape = (
                 batch_size * num_beam_groups,
@@ -164,6 +165,7 @@ def _check_attentions_for_generate(
                 [layer_attention.shape for layer_attention in iter_attentions], [expected_shape] * len(iter_attentions)
             )
 
+    # overwrite because HybridCache has fixed length for key/values
     def _check_past_key_values_for_generate(self, batch_size, past_key_values, seq_length, config, num_beam_groups=1):
         self.assertIsInstance(past_key_values, HybridCache)