docs: function getWHIgnoreDisplay(elem) {
    var val = undefined;
    var args = arguments;
    // in case elem is window
    // elem.offsetWidth === undefined
    if (elem.offsetWidth !== 0) {
      val = getWH.apply(undefined, args);
    } else {
      swap(elem, cssShow, function () {
        val = getWH.apply(undefined, args);
      });
    }
    return val;
  }