Bug 49182 What should canceling setRawClasspath do ?
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/viewsupport/GoToBackProgressMonitorDialog.java
/**
		 * Processes events or waits until this modal context thread terminates.
		 */
		public void block() {
			if (display == Display.getCurrent()) {
				while (continueEventDispatching && !progressMonitor.isInBackground()) {
					if (!display.readAndDispatch())
						display.sleep();
				}
			} else {
				try {
					join();
				} catch (InterruptedException e) {
				}
			}
		}
	}
	
	/**
	 * Name to use for task when normal task name is empty string.
	 */
	private static String DEFAULT_TASKNAME= JFaceResources.getString("ProgressMonitorDialog.message"); 
	
	/**
	 * Constants for label and monitor size
	 */
	private static int LABEL_DLUS = 21;
	private static int BAR_DLUS = 9;
	/**