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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def ctcp_reply(self, command, dst, message=None):
 """ Sends a reply to a CTCP request. :param command: CTCP command to use. :type command: str :param dst: sender of the initial request. :type dst: str :param message: data to attach to the reply. :type message: str """

        if message is None:
            raw_cmd = u'\x01{0}\x01'.format(command)
        else:
            raw_cmd = u'\x01{0} {1}\x01'.format(command, message)
        self.notice(dst, raw_cmd)