revert black formatting to conform with lib style

transformers/modeling_seq2seq.py

@@ -43,13 +43,7 @@ class PreTrainedSeq2seq(PreTrainedModel):
         self.decoder = decoder
 
     @classmethod
-    def from_pretrained(
-        cls,
-        encoder_pretrained_model_name_or_path,
-        decoder_pretrained_model_name_or_path,
-        *model_args,
-        **kwargs
-    ):
+    def from_pretrained(cls, encoder_pretrained_model_name_or_path, decoder_pretrained_model_name_or_path, *model_args, **kwargs):
         r""" Instantiates an encoder and a decoder from one or two base classes
         of the library from pre-trained model checkpoints.
 
@@ -190,7 +184,7 @@ class Model2Model(PreTrainedSeq2seq):
     def tie_weights(self):
         """ Tying the encoder and decoders' embeddings together.
 
-        We need for each to get down to the embedding weights. However the
+       We need for each to get down to the embedding weights. However the
         different model classes are inconsistent to that respect:
         - BertModel: embeddings.word_embeddings
         - RoBERTa: embeddings.word_embeddings