function createSelectorList() {
        var doc = DocumentManager.getCurrentDocument();
        if (!doc) {
            return;
        }

        var docText = doc.getText();
        return CSSUtils.extractAllSelectors(docText, doc.getLanguage().getMode());
    }
Returns a list of information about selectors for a single document. This array is populated
by createSelectorList()
@return {?Array.<FileLocation>}