code: public Future<Date> getDateOfDataInCache(Class<?> clazz, final Object cacheKey) throws CacheCreationException {
          return executeCommand(new GetDateOfDataInCacheCommand(this, clazz, cacheKey));
      }
docs: Returns the last date of storage of a given data into the cache.
  @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
  @return the date at which data has been stored in cache. Null if no such
  data is in Cache.
  @throws CacheLoadingException
  Exception thrown when a problem occurs while loading data
  from cache.