code: function toggleClass(element, className, force) {
  	  if (is$1.nodeList(element)) {
  	    return Array.from(element).map(function (e) {
  	      return toggleClass(e, className, force);
  	    });
  	  }
  
  	  if (is$1.element(element)) {
  	    var method = 'toggle';
  
  	    if (typeof force !== 'undefined') {
  	      method = force ? 'add' : 'remove';
  	    }
  
  	    element.classList[method](className);
  	    return element.classList.contains(className);
  	  }
  
  	  return false;
  	}
docs: Mirror Element.classList.toggle, with IE compatibility for "force" argument