fEditor= editor;
	public TemplateContext(ITextViewer viewer, int completionPosition, ICompilationUnit unit,	    String contextType)	{		Assert.isNotNull(viewer);		Assert.isTrue(completionPosition >= 0);				fViewer= viewer;		fEnd= completionPosition;		fUnit= unit;		fType= contextType;				String source= fViewer.getDocument().get();		fStart= guessStart(source, fEnd, contextType);								fKey= source.substring(fStart, fEnd);	}