return 0 <= offset  && offset <= documentLength && 0 <= end && end <= documentLength;
return 0 <= offset  && offset <= documentLength && 0 <= end && end <= documentLength && length >= 0;
		private boolean isValidSelection(int offset, int length) {			IDocumentProvider provider= getDocumentProvider();			if (provider != null) {				IDocument document= provider.getDocument(getEditorInput());				if (document != null) {					int end= offset + length;					int documentLength= document.getLength();					return 0 <= offset  && offset <= documentLength && 0 <= end && end <= documentLength;				}			}			return false;		}