def METHOD_NAME(self, data):
    """
    Received NAWS. (Window dimensions.)
    """
    if len(data) == 4:
        # NOTE: the first parameter of struct.unpack should be
        # a 'str' object. Both on Py2/py3. This crashes on OSX
        # otherwise.
        columns, rows = struct.unpack(str('!HH'), data)
        self.size_received_callback(rows, columns)
    else:
        logger.warning('Wrong number of NAWS bytes')