code: @SuppressWarnings("unchecked")
      protected <T> T getFromCache(String cacheName, String key, Class<T> clazz) {
          Object obj = getFromCache(cacheName, key);
          if (obj == null) {
              return null;
          }
          if (clazz.isAssignableFrom(obj.getClass())) {
              return (T) obj;
          }
          return null;
      }
docs: Gets an entry from cache.
  
  <p>
  Note: if the object from cache is not assignable to clazz,
  <code>null</code> is returned.
  </p>
  
  @param cacheName
  @param key
  @param clazz
  @return