code: public void clear() {
      storage.clear();
      cache.clear();
      fireEvent(StorageChangeEvent.ChangeType.CLEAR, null, null, null, null, null);
    }
docs: Removes all items in the Storage, and its cache if activated
  
  @see <a href="http://www.w3.org/TR/webstorage/#dom-storage-clear">W3C Web
  Storage - Storage.clear()</a>