001    // Copyright 2005-06 Regents of the University of California.  May be used 
002    // under the terms of the revised BSD license.  See LICENSING for details.
003    /** 
004     * @author Adrian Mettler 
005     */
006    package org.joe_e;
007    
008    /**
009     * Content-less class used solely for its unforgeable object identity.
010     * Distinct categories of tokens can be created by subclassing this class.
011     * <p>
012     * Note: this class implements Serializable in order to avoid preventing
013     * trusted (non-Joe-E) code from serializing it.  The Java Serialization API
014     * is tamed away as unsafe, and thus is not available to Joe-E code.
015     */
016    public class Token implements Immutable, Equatable, java.io.Serializable {
017        static final long serialVersionUID = 1L;    
018    }