attachOpenShadow() {
    this.innerHTML = '';
    this.attachShadow({ mode: 'open' });
    this.shadowRoot.innerHTML = `
      <style>
        div {
          align-items: center;
          background-color: #BFB;
          display: grid;
          height: 100%;
          justify-items: center;
          width: 100%;
        }
      </style>
      <div>
        <p>Shadow Root Open</p>
      </div>
    `;
  }
/**
   * Attaches an open shadow to the current element and fills it with styles
   * and markup
   */
Attaches an open shadow to the current element and fills it with styles
and markup
Attaches an open shadow to the current element and fills it with styles and markup
attachOpenShadow() {
    this.innerHTML = '';
    this.attachShadow({ mode: 'open' });
    this.shadowRoot.innerHTML = `
      <style>
        div {
          align-items: center;
          background-color: #BFB;
          display: grid;
          height: 100%;
          justify-items: center;
          width: 100%;
        }
      </style>
      <div>
        <p>Shadow Root Open</p>
      </div>
    `;
  }
attachOpenShadow ( ) { this . innerHTML = '' ; this . attachShadow ( { mode : 'open' } ) ; this . shadowRoot . innerHTML = ` ` ; }
Attaches an open shadow to the current element and fills it with styles
 and markup
Attaches an open shadow to the current element and fills it with styles and markup