code: def _verified_frame_length(frame_length, content_type):
      # type: (int, ContentType) -> int
      
      if content_type == ContentType.FRAMED_DATA and frame_length > MAX_FRAME_SIZE:
          raise SerializationError(
              "Specified frame length larger than allowed maximum: {found} > {max}".format(
                  found=frame_length, max=MAX_FRAME_SIZE
              )
          )
  
      if content_type == ContentType.NO_FRAMING and frame_length != 0:
          raise SerializationError("Non-zero frame length found for non-framed message")
  
      return frame_length
docs: Verify a frame length value for a message content type.
  
      :param int frame_length: Frame length to verify
      :param ContentType content_type: Message content type to verify against
      :return: frame length
      :rtype: int
      :raises SerializationError: if frame length is too large
      :raises SerializationError: if frame length is not zero for unframed content type