Bug 89031 [Undo/Redo] IWorkbench#getOperationSupport() marked experimental
IWorkbench#getOperationSupport() marked experimental
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/OperationStatus.java
/**
	 * NOTHING_TO_REDO indicates there was no operation available for redo.
	 */
	public static final int NOTHING_TO_REDO = 12;
	/**
	 * NOTHING_TO_UNDO indicates there was no operation available for undo.
	 */
	public static final int NOTHING_TO_UNDO = 11;
	/**
	 * OPERATION_INVALID indicates that the operation available for undo or redo
	 * is not in a state to perform the undo or redo.
	 */
	public static final int OPERATION_INVALID = 10;
	/**
	 * PLUGIN_ID identifies the plugin reporting the status.
	 */