IWorkingSet ws= PlatformUI.getWorkbench().getWorkingSetManager().getWorkingSet(workingSetName);
IWorkingSet ws= null; if (workingSetName != null && workingSetName.length() > 0) ws= PlatformUI.getWorkbench().getWorkingSetManager().getWorkingSet(workingSetName);
	public void restoreState(IMemento memento) {		String workingSetName= memento.getString(TAG_WORKING_SET_NAME);		IWorkingSet ws= PlatformUI.getWorkbench().getWorkingSetManager().getWorkingSet(workingSetName);		setWorkingSet(ws, false);	}