rem: KMMsgMetaData(KMMsgStatus aStatus) :mStatus(aStatus), mSerNum(0) {}
add: KMMsgMetaData(KMMsgStatus aStatus, Q_UINT32 aSerNum) :mStatus(aStatus), mSerNum(aSerNum) {}
context:   KMMsgMetaData(KMMsgStatus aStatus)     :mStatus(aStatus), mSerNum(0) {}