package edu.stanford.nlp.dbm;import java.util.*;/** * Interface for Objects that have a label, whose label is an Object. * There are only two methods: Object label() and Collection labels() * If there is only one label, labels() will return a collection of one label. * If there are multiple labels, label() will return the primary label,  * or a consistent arbitrary label if there is not primary label. * @author Sepandar Kamvar (sdkamvar@stanford.edu) */public abstract interface Labeled {		   /**      * Returns the primary label for this Object, or null if none have been set.     */		public Object label();    /**     * Returns the complete list of labels for this Object, which may be empty.     */		public Collection labels();}