Enable DefaultDataCollator class (#14141)

src/transformers/data/data_collator.py

@@ -74,6 +74,11 @@ def default_data_collator(features: List[InputDataClass], return_tensors="pt") -
 class DefaultDataCollator(DataCollatorMixin):
     return_tensors: str = "pt"
 
+    def __call__(self, features: List[Dict[str, Any]], return_tensors=None) -> Dict[str, Any]:
+        if return_tensors is None:
+            return_tensors = self.return_tensors
+        return default_data_collator(features, return_tensors)
+
 
 def torch_default_data_collator(features: List[InputDataClass]) -> Dict[str, Any]:
     import torch