if (fModel != null) fModel.addAnnotationModelListener(this);
	private void setModel(IAnnotationModel model) {				if (fModel != model) {			if (fModel != null)				fModel.removeAnnotationModelListener(this);			if (model != null)				model.addAnnotationModelListener(this);			fModel= model;		}				fProblemPositions.clear();		if (fModel != null) {			Iterator e= new ProblemAnnotationIterator(fModel);			while (e.hasNext()) {				Annotation a= (Annotation) e.next();				Position p= fModel.getPosition(a);				fProblemPositions.add(p);			}		}	}