async doInheritStyles() {
    if (!this.hasAttribute("inherit-style")) return;
    let url2 = this.getAttribute("inherit-style");
    if (!url2) url2 = "./index.css";
    const linkEl = document.createElement("link");
    linkEl.setAttribute("type", "text/css");
    linkEl.setAttribute("rel", "stylesheet");
    linkEl.setAttribute("href", url2);
    this.shadowRoot.appendChild(linkEl);
    console.info("[".concat(this.localName, '] Inherit-style requested. Loading: "').concat(url2, '"'));
  }
Optionally apply an external linked style sheet (called from connectedCallback)
@param {*} url The URL for the linked style sheet