@Override
    protected String convertToString(Object value) throws Throwable {
		Key key = (Key) value;
		return KeyFactory.keyToString(key);
    }
@ Override protected String convertToString ( Object value ) throws Throwable { Key key = ( Key ) value ; return KeyFactory . keyToString ( key ) ; }
Returns {@code com.google.appengine.api.datastore.Key} value as string
representation.