public V fetch(K key, Callable<V> callable) throws Exception {
        return locate(key).get(callable);
    }
public V fetch ( K key , Callable < V > callable ) throws Exception { return locate ( key ) . get ( callable ) ; }
Fetches an object from the cache. Synchronization at cache level is kept to minimum. The provider is called upon cache miss.

@param key the identity of the object
@param callable a callable to provide the object upon cache miss
@return the object requested
@throws Exception if the provider fails to create a new object