code: public Future<Boolean> isDataInCache(Class<?> clazz, final Object cacheKey, long cacheExpiryDuration) throws CacheCreationException {
          return executeCommand(new IsDataInCacheCommand(this, clazz, cacheKey, cacheExpiryDuration));
      }
docs: Tests whether some data is present in cache or not.
  @param clazz
  the class of the result to retrieve from cache.
  @param cacheKey
  the key used to store and retrieve the result of the request
  in the cache
  @param cacheExpiryDuration
  duration in milliseconds after which the content of the cache
  will be considered to be expired.
  {@link DurationInMillis#ALWAYS_RETURNED} means data in cache
  is always returned if it exists.
  {@link DurationInMillis#ALWAYS_EXPIRED} means data in cache is
  never returned.(see {@link DurationInMillis})
  @return the data has it has been saved by an ObjectPersister in cache.
  @throws CacheCreationException
  Exception thrown when a problem occurs while looking for data
  in cache.