Bug 303831 Warnings logged when trying to merge changes to an MPart's 'closeable' attribute
Warnings are printed out to syserr. --- WARNING: Unknown feature found, reconciliation may fail: Part#closeable
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/workbench/ui/internal/XMLModelReconciler.java
return null;
	}
	/**
	 * Computes and returns the original id of the specified object. The meaning of the term
	 * "original" is defined as the state of the object prior to having its state monitored via
	 * {@link #recordChanges(Object)}. The identifier for the object will be queried from the
	 * resource. If the object did not exist was not known when changes began recording,
	 * <code>null</code> will be returned.
	 * 
	 * @param object
	 *            the object to query an id for
	 * @return an id suitable for looking up the object, or <code>null</code> if the object did not
	 *         exist or was not known within the scope of the originally monitored object
	 */
	private String getOriginalId(Object object) {
		EObject reference = (EObject) object;
		EObject originalContainer = getOriginalContainer(reference);
		
		if (originalContainer == null) {
			return null;
		}
		if (originalContainer != changeDescription) {
			EObject container = originalContainer;
			while (container != rootObject) {
				container = getOriginalContainer(container);
				if (container == null) {
					return null;
				}
			}
		}