function sortLines(model, selection, descending) {
        var data = getSortData(model, selection, descending);
        if (!data) {
            return null;
        }
        return editOperation_1.EditOperation.replace(new range_1.Range(data.startLineNumber, 1, data.endLineNumber, model.getLineMaxColumn(data.endLineNumber)), data.after.join('\n'));
    }
Generate commands for sorting lines on a model.