unwrapMatches(node) {
    const parent = node.parentNode;
    let docFrag = document.createDocumentFragment();
    while (node.firstChild) {
      docFrag.appendChild(node.removeChild(node.firstChild));
    }
    parent.replaceChild(docFrag, node);
    if (!this.ie) { // use browser's normalize method
      parent.normalize();
    } else { // custom method (needs more time)
      this.normalizeTextNode(parent);
    }
  }
Unwraps the specified DOM node with its content (text nodes or HTML)
without destroying possibly present events (using innerHTML) and normalizes
the parent at the end (merge splitted text nodes)
@param  {HTMLElement} node - The DOM node to unwrap
@access protected