/**

  * Copyright 2005-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  * http://www.opensource.org/licenses/ecl2.php

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.kuali.rice.kew.api.identity;

 import java.io.Serializable;

 /**

  * Superinterface of UserId and GroupId

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public interface Id extends Serializable {

     /**

      * Returns true if this Id has an empty value. Empty Ids can't be used as keys in a Hash,

      * among other things.

      *

      * @return true if this instance doesn't have a value

      */

     public boolean isEmpty();

 }