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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 *
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package java.util;

/**
 * A class can implement the {@code Observer} interface when it
 * wants to be informed of changes in observable objects.
 *
 * @author  Chris Warth
 * @see     java.util.Observable
 * @since   1.0
 *
 * @deprecated
 * This interface has been deprecated. See the {@link Observable}
 * class for further information.
 */
@Deprecated(since="9")
public interface Observer {
    /**
     * This method is called whenever the observed object is changed. An
     * application calls an {@code Observable} object's
     * {@code notifyObservers} method to have all the object's
     * observers notified of the change.
     *
     * @param   o     the observable object.
     * @param   arg   an argument passed to the {@code notifyObservers}
     *                 method.
     */
    void update(Observable o, Object arg);
}