docs: function legacyAttrClass(domRef, oldClass, newValue, anim){
        var newClass = newValue || '';
  
        if (newClass != oldClass)
        {
          var className = domRef.className;
          var classNameIsObject = typeof className != 'string';
          var classList;
  
          if (classNameIsObject)
            className = className.baseVal;
  
          classList = className.split(WHITESPACE);
  
          if (oldClass)
            basis.array.remove(classList, oldClass);
  
          if (newClass)
          {
            classList.push(newClass);
  
            if (anim)
            {
              basis.array.add(classList, newClass + '-anim');
              basis.nextTick(function(){
                var classList = (classNameIsObject ? domRef.className.baseVal : domRef.className).split(WHITESPACE);
  
                basis.array.remove(classList, newClass + '-anim');
  
                if (classNameIsObject)
                  domRef.className.baseVal = classList.join(' ');
                else
                  domRef.className = classList.join(' ');
              });
            }
          }
  
          if (classNameIsObject)
            domRef.className.baseVal = classList.join(' ');
          else
            domRef.className = classList.join(' ');
        }
  
        return newClass;
      }