@Override
  public InternalDistributedMember getMemberToMasqueradeAs() {
    if (txMemberId == null) {
      return getSender();
    }
    return txMemberId;
  }
Transaction operations override this method to do actual work

@param txId The transaction Id to operate on
@return true if TXMessage should send a reply false otherwise
geode-core/src/main/java/org/apache/geode/internal/cache/TXMessage.java