docs: def to_bytes(self, frame, state):
          """
          Convert a single frame into bytes that can be transmitted on
          the stream.
  
          :param frame: The frame to convert.  Should be the same type
                        of object returned by ``to_frame()``.
          :param state: An instance of ``FramerState``.  This object may
                        be used to track information across calls to the
                        method.
  
          :returns: Bytes that may be transmitted on the stream.
          """
  
          # Generate the bytes from the frame
          frame = six.binary_type(frame)
          return self.encode_length(frame, state) + frame