old_contents: from .transformer import Transformer, TransformerAttentionDecoder, TransformerAttentionEncoder
  from .bytenet import ByteNet
  from .seq2seq_base import Seq2Seq
  from .seq2seq_generic import HybridSeq2Seq
  from .recurrent import RecurrentAttentionSeq2Seq, RecurrentEncoder, RecurrentAttentionDecoder
  from .img2seq import Img2Seq
  from .prevasive import Prevasive
  
  __all__ = ['RecurrentAttentionSeq2Seq',
             'Transformer', 'Img2Seq', 'HybridSeq2Seq', 'Prevasive']
  
new_contents: from .transformer import Transformer, TransformerAttentionDecoder, TransformerAttentionEncoder
  from .bytenet import ByteNet
  from .seq2seq_base import Seq2Seq
  from .seq2seq_generic import HybridSeq2Seq
  from .recurrent import RecurrentAttentionSeq2Seq, RecurrentEncoder, RecurrentAttentionDecoder
  from .img2seq import Img2Seq
  
  __all__ = ['RecurrentAttentionSeq2Seq',
             'Transformer', 'Img2Seq', 'HybridSeq2Seq']
  
subject: remove prevasive