@Override
    public String toString() {
      // bug 37189 These strings are a work-around for an escaped reference
      // in ReplyProcessor21 constructor
      String msgsBeingProcessedStr = String.valueOf(msgsBeingProcessed.get());
      String regionStr = (region == null) ? "nullRef"
          : region.getFullPath();
      String numMembersStr = (members == null) ? "nullRef" : String.valueOf(numMembers());
      // String membersToStr = (this.members == null) ? "nullRef" : membersToString();

      return "<" + getClass().getName() + " " + getProcessorId() + " waiting for "
          + numMembersStr + " replies" + (exception == null ? "" : (" exception: " + exception))
          + " from " + membersToString() + "; waiting for " + msgsBeingProcessedStr
          + " messages in-flight; " + "region=" + regionStr + "; abort=" + abort + ">";
    }
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