code: def unpack(self, buff, offset=0):
          
          unpack_length = UBInt16()
          unpack_length.unpack(buff, offset)
          super().unpack(buff[:offset+unpack_length], offset)
docs: Unpack a binary message into this object's attributes.
  
          Pass the correct length for list unpacking.
  
          Args:
              buff (bytes): Binary data package to be unpacked.
              offset (int): Where to begin unpacking.