code: function removeClass(element, className) {
      if (!hasClassNameProperty(element)) {
          return;
      }
      element.className = element.className
          .replace(className, '')
          .replace(/^\s+|\s+$/g, '')
          .replace(/\s\s/g, ' ');
  }
docs: Removes a class name from the element's list of class names.
  
  @static
  @param  {DOMElement} element The DOM element to modify.
  @param  {string} className The name to remove.
  @example
  
  addClass(el, 'container');
  
  hasClass(el, 'container');
  // => true
  
  removeClass(el, 'container');
  
  hasClass(el, 'container');
  // => false