if (fWorkingSets.size() == 0) { JavaCore.removeElementChangedListener(fListener); fListener= null; }
	public boolean remove(IWorkingSet workingSet) {		boolean result= false;		synchronized(fWorkingSets) {			result= fWorkingSets.remove(workingSet);		}		if (fWorkingSets.size() == 0) {			JavaCore.removeElementChangedListener(fListener);			fListener= null;		}		return result;	}