docs: function normalAttrClass(domRef, oldClass, newValue, anim){
        var classList = domRef.classList;
  
        // IE11 and lower doesn't support classList for SVG
        if (!classList)
          return legacyAttrClass(domRef, oldClass, newValue, anim);
  
        var newClass = newValue || '';
  
        if (newClass != oldClass)
        {
          if (oldClass)
            domRef.classList.remove(oldClass);
  
          if (newClass)
          {
            domRef.classList.add(newClass);
  
            if (anim)
            {
              domRef.classList.add(newClass + '-anim');
              basis.nextTick(function(){
                domRef.classList.remove(newClass + '-anim');
              });
            }
          }
        }
  
        return newClass;
      }