public static byte[] updateAllianceRank(MapleGuildCharacter mgc) {
            MaplePacketLittleEndianWriter mplew = new MaplePacketLittleEndianWriter();

            mplew.writeShort(SendPacketOpcode.ALLIANCE_OPERATION.getValue());
            mplew.write(27);
            mplew.writeInt(mgc.getId());
            mplew.write(mgc.getAllianceRank());

            return mplew.getPacket();
        }