public ICompletionProposal[] computeQuickAssistProposals(IQuickAssistInvocationContext quickAssistContext) {
ISourceViewer viewer= quickAssistContext.getSourceViewer();
int documentOffset= quickAssistContext.getOffset();
int length= viewer != null ? viewer.getSelectedRange().y : -1;
TextInvocationContext context= new TextInvocationContext(viewer, documentOffset, length);
IAnnotationModel model= viewer.getAnnotationModel();
if (model == null)
return fgNoSuggestionsProposal;