'Get \'length\' bytes starting at \'position\'.
Position is start of payload (first four packet header bytes are not
included) starting at index \'0\'.
No error checking is done.  If requesting outside end of buffer
an empty string (or string shorter than \'length\') may be returned!'

def get_bytes(self, position, length=1):

    return self._data[position:(position + length)]
