text: define([
     "../../core",
     "../../selector"
  
     // css is assumed
  ], function (jQuery) {
  
     return function (elem, el) {
  
        // isHidden might be called from jQuery#filter function;
        // in that case, element will be second argument
        elem = el || elem;
        return jQuery.css(elem, "display") === "none" || !jQuery.contains(elem.ownerDocument, elem);
     };
  });
  