code: function isElement(o){
    var DOM_ELEMENT = 1
    return (
      typeof HTMLElement === "object" ? o instanceof HTMLElement : //DOM2
        o && typeof o === "object" && o !== null && o.nodeType === DOM_ELEMENT && typeof o.nodeName==="string"
    )
  }
docs: Returns true if it is a DOM element https://stackoverflow.com/a/384380/2835973