code: public void register(CacheEntryListenerConfiguration<K, V> configuration) {
      if (configuration.getCacheEntryListenerFactory() == null) {
        return;
      }
      EventTypeAwareListener<K, V> listener = new EventTypeAwareListener<>(
          configuration.getCacheEntryListenerFactory().create());
  
      CacheEntryEventFilter<K, V> filter = event -> true;
      if (configuration.getCacheEntryEventFilterFactory() != null) {
        filter = new EventTypeFilter<>(listener,
            configuration.getCacheEntryEventFilterFactory().create());
      }
  
      Registration<K, V> registration = new Registration<>(configuration, filter, listener);
      dispatchQueues.putIfAbsent(registration, CompletableFuture.completedFuture(null));
    }
docs: Registers a cache entry listener based on the supplied configuration.
  
  @param configuration the listener's configuration.