Bug 176450 Support link to CSS Feature(Model Part)
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/activity/NotificationEvent.java
/**
	 * Event is being sent to the elements that use an element.
	 */
	public static final int ELEMENT_CLIENT = 4;
	/**
	 * Event is being sent to the elements that use a structure defined in
	 * report design.
	 */
	public static final int STRUCTURE_CLIENT = 5;
	/**
	 * The design element that changed.
	 */
	protected DesignElement target = null;
	/**
	 * The sender of the event. This is generally the UI that made the change.
	 * This allows the UI to ignore, if it chooses, events that indicate changes
	 * that the that UI made itself.
	 */
	protected Object sender = null;
	/**
	 * The current delivery path for the notification. Updated as the event
	 * works though the delivery system.
	 */
	protected int deliveryPath = DIRECT;
	/**
	 * Default constructor.
	 */
	public NotificationEvent( )
	{
	}