private Status getStatus(InternalDistributedMember sender) {
      Status status;
      synchronized (this) {
        status = statusMap.get(sender);
        if (status == null) {
          status = new Status();
          statusMap.put(sender, status);
        }
      }
      return status;
    }
Overridden to wait for messages being currently processed: This situation can come about if a
member departs while we are still processing data from that member
geode-core/src/main/java/org/apache/geode/internal/cache/InitialImageOperation.java