pm.beginTask("", 1); pm.setTaskName("Performing changes...");
	public void perform(ChangeContext context, IProgressMonitor pm) throws JavaModelException{		if (!isActive()){			fUndoChange= new NullChange();		} else{			fUndoChange= new CompositeChange(fName, createUndoList(context, pm));		}			pm.done();	}