Update utils.py

Author: Cyrilvallez

src/transformers/generation/utils.py

@@ -656,6 +656,7 @@ def prepare_inputs_for_generation(
             if causal_mask_creation_function is None:  # can't be found
                 output_attentions = kwargs.get("output_attentions", False)
                 token_type_ids = getattr(model_input, "token_type_ids", None)
+                # Some models may overwrite the general one
                 causal_mask_creation_function = getattr(self, "create_masks_for_generate", create_masks_for_generate)
                 attention_mask = causal_mask_creation_function(
                     config=self.config,