synchronized void respondWithGrant(long leaseExpireTime) {
      response.responseCode = DLockResponseMessage.GRANT;
      response.leaseExpireTime = leaseExpireTime;
      response.dlsSerialNumber = dlsSerialNumber;
      sendResponse();
    }
Callers must be synchronized on this
geode-core/src/main/java/org/apache/geode/distributed/internal/locks/DLockRequestProcessor.java