code: function outerWidth(margin) {
    var s, style;
    if(!this.length) {
      return null;
    }
    s = this.dom[0].getClientRects()[0].width;
    if(!margin) {
      style = window.getComputedStyle(this.dom[0], null);
      s -= parseInt(style.getPropertyValue('margin-top'));
      s -= parseInt(style.getPropertyValue('margin-bottom'));
    }
    return s;
  }
docs: Get the current computed width for the first element in the set of
  matched elements, including padding, border, and optionally margin.
  
  Returns a number (without "px") representation of the value or null
  if called on an empty set of elements.