function equalSnapshot(options) {
    const el = chai.util.flag(this, 'object');
    let html;
    if (utils.flag(this, 'shadowDom')) {
      html = getShadowDomHtml(el);
    } else if (utils.flag(this, 'lightDom')) {
      html = getLightDomHtml(el);
    } else {
      html = el;
    }
    return assertHtmlEqualsSnapshot.call(this, html, utils.flag(this, 'negate'), options);
  }
Snapshot assertion for `should` and `expect` interfaces.
@this {Chai.AssertionStatic}