function toggleClassAndInjectStyleRule(pseudoType)
            {
                const classNamePrefix = "__web-inspector-hide";
                const classNameSuffix = "-shortcut__";
                const styleTagId = "__web-inspector-hide-shortcut-style__";
                var selectors = [];
                selectors.push("html /deep/ .__web-inspector-hide-shortcut__");
                selectors.push("html /deep/ .__web-inspector-hide-shortcut__ /deep/ *");
                selectors.push("html /deep/ .__web-inspector-hidebefore-shortcut__::before");
                selectors.push("html /deep/ .__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);

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

                style = document.createElement("style");
                style.id = styleTagId;
                style.type = "text/css";
                style.textContent = rule;
                document.head.appendChild(style);
            }
@param {?string} pseudoType
@suppressGlobalPropertiesCheck
@suppressReceiverCheck
@this {!Element}