code: function getNetContainerWidth ( $container, isWindow, cache ) {
          var width;
  
          if ( cache && cache.netContainerWidth !== undefined ) {
              width = cache.netContainerWidth;
          } else {
              width = isWindow ?
                      getWindowDimension( $container, "Width" ) :
                      $container.innerWidth() - getContainerScrollbarWidths( $container, cache ).vertical;
  
              if ( cache ) cache.netContainerWidth = width;
          }
  
          return width;
      }
docs: Gets the width of a jQuery-wrapped container, excluding scroll bars. Also supports quirks mode for window
  containers, unlike jQuery's $( window ).width(). Makes use of caching if a cache object is provided.
  
  @param   {jQuery}  $container
  @param   {boolean} isWindow    required to speed up the process
  @param   {Object}  [cache]
  @returns {number}