Bug 94400 [Undo] - After successful undo, should operation be disposed by framework if it cannot be redone?
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
System.out.println();
		}
		notifyListeners(new OperationHistoryEvent(
				OperationHistoryEvent.OPERATION_CHANGED, this, operation));
	}
	/*
	 * A history notification is about to be sent. Notify the operation before
	 * hand if it implements IHistoryNotificationAwareOperation.
	 * 
	 * This method is provided for legacy undo frameworks that rely on
	 * notification from their undo managers before any listeners are notified
	 * about changes in the operation.
	 */
	private void preNotifyOperation(IUndoableOperation operation,
			OperationHistoryEvent event) {
		if (operation instanceof IAdvancedUndoableOperation) {
			try {
				((IAdvancedUndoableOperation) operation).aboutToNotify(event);
			} catch (Exception e) {
				handleNotificationException(e);
			}
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IOperationHistory#redo(org.eclipse.core.commands.operations.IUndoContext,
	 *      org.eclipse.core.runtime.IProgressMonitor,
	 *      org.eclipse.core.runtime.IAdaptable)
	 */