code: @Override
     public <K, V> RemoteCache<K, V> getCache(String cacheName) {
        return getCache(cacheName, configuration.forceReturnValues(), null, null);
     }
docs: Retrieves a named cache from the remote server if the cache has been
  defined, otherwise if the cache name is undefined, it will return null.
  
  @param cacheName name of cache to retrieve
  @return a cache instance identified by cacheName or null if the cache
  name has not been defined