private boolean isLockForDrainingHeld() {
      return eventAddDrainLock.writeLock().isHeldByCurrentThread();
    }
Represents a conflatable and event processed while a client was registering.
This needs to be queued and processed after registration is complete. The conflatable
is what we will actually be delivering to the MessageDispatcher (and thereby adding
to the HARegionQueue). The internal cache event is required to rehydrate the filter
info and determine if the client which was registering does have a CQ that matches or
has registered interest in the key.
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/ClientRegistrationEventQueueManager.java