Update files from the datasets library (from 1.6.1)

Release notes: https://github.com/huggingface/datasets/releases/tag/1.6.1

mutual_friends.py

@@ -144,7 +144,7 @@ class MutualFriends(datasets.GeneratorBasedBuilder):
         ]
 
     def _generate_examples(self, filepath):
-        """ Yields examples. """
+        """Yields examples."""
         with open(filepath, encoding="utf-8") as f:
             mutualfriends = json.load(f)