function toggleClassAndInjectStyleRule(pseudoType, hidden)
            {
                const classNamePrefix = "__web-inspector-hide";
                const classNameSuffix = "-shortcut__";
                const styleTagId = "__web-inspector-hide-shortcut-style__";
                var selectors = [];
                selectors.push(".__web-inspector-hide-shortcut__");
                selectors.push(".__web-inspector-hide-shortcut__ *");
                selectors.push(".__web-inspector-hidebefore-shortcut__::before");
                selectors.push(".__web-inspector-hideafter-shortcut__::after");
                var selector = selectors.join(", ");
                var ruleBody = "    visibility: hidden !important;";
                var rule = "\n" + selector + "\n{\n" + ruleBody + "\n}\n";
                var className = classNamePrefix + (pseudoType || "") + classNameSuffix;
                this.classList.toggle(className, hidden);

                var localRoot = this;
                while (localRoot.parentNode)
                    localRoot = localRoot.parentNode;
                if (localRoot.nodeType === Node.DOCUMENT_NODE)
                    localRoot = document.head;

                var style = localRoot.querySelector("style#" + styleTagId);
                if (style)
                    return;

                style = document.createElement("style");
                style.id = styleTagId;
                style.type = "text/css";
                style.textContent = rule;

                localRoot.appendChild(style);
            }
@param {?string} pseudoType
@param {boolean} hidden
@suppressGlobalPropertiesCheck
@suppressReceiverCheck
@this {!Element}