Inserts element into the DOM at the specified location.
To see the possible values for where, read the doc for
insertAdjacentHtml.
See also:
Element insertAdjacentElement(String where, Element element) {
  if (JS('bool', '!!#.insertAdjacentElement', this)) {
    _insertAdjacentElement(where, element);
  } else {
    _insertAdjacentNode(where, element);
  }
  return element;
}