public static void send(MessageWithReply reqMsg, DistributionManager dm, ArrayList grantors,
        ArrayList grantorVersions, ArrayList grantorSerialNumbers, ArrayList nonGrantors) {
      ElderInitReplyMessage m = new ElderInitReplyMessage();
      m.grantors = grantors;
      m.grantorVersions = grantorVersions;
      m.grantorSerialNumbers = grantorSerialNumbers;
      m.nonGrantors = nonGrantors;
      m.processorId = reqMsg.getProcessorId();
      m.setRecipient(reqMsg.getSender());
      dm.putOutgoing(m);
    }
Note the synchronization; we can only process one response at a time.
geode-core/src/main/java/org/apache/geode/distributed/internal/locks/ElderInitProcessor.java