code: def dump(self, stream=None):
          
          if stream is None:
              stream = BytesIO()
  
          if isinstance(stream, bytes):
              stream = BytesIO(stream)
  
          stream = self.codec.compress(stream)
          self.fs.dump(stream)
  
          return self
docs: Writes a stream to a file.
  
          :param stream:
              A BytesIO instance. ``bytes`` are also possible and are converted
              to BytesIO.
  
          :rtype: File