code: function(child) {
        return this.length ? (/^o/.test(typeof child) ? this[0] !== child[0] && this[0].contains(child[0]) : this[0].querySelector(child) !== null) : false;
      }
docs: contains method
  check if child is contained in this element
  @param  {(string|object)} child - element or css selector
  @return {boolean}