Bug 315281 update copyrights for 3.6
bundles/org.eclipse.core.databinding.observable/src/org/eclipse/core/databinding/observable/map/ComputedObservableMap.java
* @param removedKey
	 */
	protected abstract void unhookListener(Object removedKey);
	/**
	 * @param addedKey
	 */
	protected abstract void hookListener(Object addedKey);
	/**
	 * @param key
	 * @return the value for the given key
	 */
	protected abstract Object doGet(Object key);
	/**
	 * @param key
	 * @param value
	 * @return the old value for the given key
	 */
	protected abstract Object doPut(Object key, Object value);
	public boolean isStale() {
		return super.isStale() || keySet.isStale();
	}
	public synchronized void dispose() {
		unhookListeners();
		entrySet = null;
		keySet = null;
		setChangeListener = null;
		super.dispose();
	}
}