fix(FileWithMetadata): Hand edit for FileWithMetadata _to_dict()

Author: ehdsouza

ibm_watson/visual_recognition_v4.py

@@ -2457,7 +2457,7 @@ def _to_dict(self):
         """Return a json dictionary representing this model."""
         _dict = {}
         if hasattr(self, 'data') and self.data is not None:
-            _dict['data'] = self.data._to_dict()
+            _dict['data'] = self.data.__str__()
         if hasattr(self, 'filename') and self.filename is not None:
             _dict['filename'] = self.filename
         if hasattr(self, 'content_type') and self.content_type is not None: