nction html(strings, ...values) {
        const template = document.createElement('template');
        template.innerHTML = values.reduce((acc, v, idx) =>
            acc + v + strings[idx + 1], strings[0]);
        return template;
      };

      const defineTestElement = (name, template, connected) => {
        customElements.define(name, class extends HTMLElement {
          connectedCallback() {
            if (!this._initialized) {
              this._initialized = true;
              if (template) {
