Bug 315281 update copyrights for 3.6
bundles/org.eclipse.core.databinding.observable/src/org/eclipse/core/databinding/observable/Diffs.java
}
			public Set getChangedKeys() {
				return Collections.EMPTY_SET;
			}
			public Object getNewValue(Object key) {
				return newValue;
			}
			public Object getOldValue(Object key) {
				return null;
			}
			public Set getRemovedKeys() {
				return Collections.EMPTY_SET;
			}
		};
	}
	/**
	 * @param existingKey
	 * @param oldValue
	 * @param newValue
	 * @return a map diff
	 */
	public static MapDiff createMapDiffSingleChange(final Object existingKey,
			final Object oldValue, final Object newValue) {
		return new MapDiff() {
			public Set getAddedKeys() {
				return Collections.EMPTY_SET;
			}
			public Set getChangedKeys() {
				return Collections.singleton(existingKey);
			}