code: def read_short(source, offset):
      
      try:
          (short,) = struct.unpack_from(">H", source, offset)
          return short, offset + struct.calcsize(">H")
      except struct.error:
          raise SerializationError("Bad format of serialized context.")
docs: Reads a number from a byte array.
  
      :param bytes source: Source byte string
      :param int offset: Point in byte string to start reading
      :returns: Read number and offset at point after read data
      :rtype: tuple of ints
      :raises: SerializationError if unable to unpack