@Override
  public InternalDistributedMember getMemberToMasqueradeAs() {
    if (txMemberId == null) {
      return getSender();
    } else {
      return txMemberId;
    }
  }
check to see if the distributed system is closing

@return true if the distributed system is closing
geode-core/src/main/java/org/apache/geode/internal/cache/DistributedRegionFunctionStreamingMessage.java