code: function(className) {
          var cs = className.split(' ');
          return this.each(function(el) {
              cs.forEach(function(clazz) {
                if (hasClass(el, clazz) === false) {
                  el.className = trim(el.className + ' ' + clazz);
                }
              });
          });
      }
docs: addClass
  --------
  
  Adds a class to all of the elements in the collection.
  
  ### syntax ###
  
  x$( selector ).addClass( className );
  
  ### arguments ###
  
  - className `String` is the name of the CSS class to add.
  
  ### example ###
  
  x$('.foo').addClass('awesome');