send MGMT_ANNOUNCE_BEGIN message to a given destination

        Returns:
            True: successful to send MGMT_ANNOUNCE_BEGIN message.
            False: fail to send MGMT_ANNOUNCE_BEGIN message.

def MGMT_ANNOUNCE_BEGIN(self, sAddr, xCommissionerSessionId, listChannelMask, xCount, xPeriod):
        """send MGMT_ANNOUNCE_BEGIN message to a given destination

        Returns:
            True: successful to send MGMT_ANNOUNCE_BEGIN message.
            False: fail to send MGMT_ANNOUNCE_BEGIN message.
        """
        print '%s call MGMT_ANNOUNCE_BEGIN' % self.port
        channelMask = ''
        channelMask = self.__ChannelMaskListToStr(listChannelMask)
        try:
            cmd = WPANCTL_CMD + 'commissioner announce-begin %s %s %s %s' % (channelMask, xCount, xPeriod, sAddr)
            print cmd
            return self.__sendCommand(cmd) != 'Fail'
        except Exception, e:
            ModuleHelper.WriteIntoDebugLogger('MGMT_ANNOUNCE_BEGIN() error: ' + str(e))