Bug 44443 [Tasks] Problems View should 'filter' more efficiently
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/ActionDeleteCompleted.java
private MarkerRegistry registry;
	private IWorkbenchPart part;
	/**
	 * @param provider
	 * @param text
	 */
	public ActionDeleteCompleted(IWorkbenchPart part, ISelectionProvider provider, MarkerRegistry registry) {
		super(provider, Messages.getString("deleteCompletedAction.title")); 
		this.part = part;
		this.registry = registry;
		setEnabled(false);
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.jface.action.Action#run()
	 */
	public void run() {
		final List completed = getCompletedTasks();
		
		if (completed.size() == 0) {
			MessageDialog.openInformation(
				part.getSite().getShell(),