protected void registerClientInterest(String regionName, Object keyOfInterest,
      final @NotNull InterestType interestType,
      boolean isDurable, boolean sendUpdatesAsInvalidates, boolean flushState) {
    ClientInterestList cil =
        cils[RegisterInterestTracker.getInterestLookupIndex(isDurable, false)];
    cil.registerClientInterest(regionName, keyOfInterest, interestType, sendUpdatesAsInvalidates);
    if (flushState) {
      flushForInterestRegistration(regionName,
          _cache.getDistributedSystem().getDistributedMember());
    }
    HARegionQueue queue = getHARegionQueue();
    if (queue != null) { // queue is null during initialization
      queue.setHasRegisteredInterest(true);
    }
  }
Registers interest in the input region name and key

@param regionName The fully-qualified name of the region in which to register interest
@param keyOfInterest The key in which to register interest
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/CacheClientProxy.java