function _addRule(selectorName, inlineEditor, path) {
        DocumentManager.getDocumentForPath(path).done(function (styleDoc) {
            var newRuleInfo = CSSUtils.addRuleToDocument(styleDoc, selectorName, Editor.getUseTabChar(path), Editor.getSpaceUnits(path));
            inlineEditor.addAndSelectRange(selectorName, styleDoc, newRuleInfo.range.from.line, newRuleInfo.range.to.line);
            inlineEditor.editor.setCursorPos(newRuleInfo.pos.line, newRuleInfo.pos.ch);
        });
    }
@private
Add a new rule for the given selector to the given stylesheet, then add the rule to the
given inline editor.
@param {string} selectorName The selector to create a rule for.
@param {MultiRangeInlineEditor} inlineEditor The inline editor to display the new rule in.
@param {string} path The path to the stylesheet file.