code: function positionInNodeList(element, nodeList) {
    for (var i = 0; i < nodeList.length; i++) {
      if (element === nodeList[i]) {
        return i;
      }
    }
    return -1;
  }
docs: Find the position of [element] in [nodeList].
  @returns an index of the match, or -1 if there is no match