code: public <T> void getFromCache(final Class<T> clazz, final Object requestCacheKey, final long cacheExpiryDuration, final RequestListener<T> requestListener) {
          final SpiceRequest<T> request = new SpiceRequest<T>(clazz) {
  
              @Override
              public T loadDataFromNetwork() throws Exception {
                  return null;
              }
  
              @Override
              public boolean isAggregatable() {
                  return false;
              }
          };
          final CachedSpiceRequest<T> cachedSpiceRequest = new CachedSpiceRequest<T>(request, requestCacheKey, cacheExpiryDuration);
          cachedSpiceRequest.setOffline(true);
          execute(cachedSpiceRequest, requestListener);
      }
docs: Get some data previously saved in cache with key <i>requestCacheKey</i>
  with maximum time in cache : <i>cacheDuration</i> millisecond and
  register listeners to notify when request is finished. This method
  executes a SpiceRequest with no network processing. It just checks
  whatever is in the cache and return it, including null if there is no
  such data found in cache.
  @param clazz
  the class of the result to retrieve from cache.
  @param requestCacheKey
  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})
  @param requestListener
  the listener to notify when the request will finish. If
  nothing is found in cache, listeners will receive a null
  result on their
  {@link RequestListener#onRequestSuccess(Object)} method. If
  something is found in cache, they will receive it in this
  method. If an error occurs, they will be notified via their
  {@link RequestListener#onRequestFailure(com.octo.android.robospice.persistence.exception.SpiceException)}
  method.