code: function (elm, classNames) {
          classNames = utils.isArray(classNames) ? classNames :
              utils.trim(classNames).replace(/[ ]{2,}/g,' ').split(' ');
          for(var i = 0,ci,cls = elm.className;ci=classNames[i++];){
              cls = cls.replace(new RegExp('\\b' + ci + '\\b'),'')
          }
          cls = utils.trim(cls).replace(/[ ]{2,}/g,' ');
          if(cls){
              elm.className = cls;
          }else{
              domUtils.removeAttributes(elm,['class']);
          }
      }
docs: 删除元素element指定的className
  @method removeClasses
  @param { Element } ele 需要删除class的元素节点
  @param { String } classNames 需要删除的className， 多个className之间以空格分开
  @example
  ```html
  <span id="test" class="test1 test2 test3">xxx</span>
  
  <script>
  
  var testNode = document.getElementById( "test" );
  UE.dom.domUtils.removeClasses( testNode, "test1 test2" );
  
  //output: test3
  console.log( testNode.className );
  
  </script>
  ```
   
  删除元素element指定的className
  @method removeClasses
  @param { Element } ele 需要删除class的元素节点
  @param { Array } classNames 需要删除的className数组
  @example
  ```html
  <span id="test" class="test1 test2 test3">xxx</span>
  
  <script>
  
  var testNode = document.getElementById( "test" );
  UE.dom.domUtils.removeClasses( testNode, ["test1", "test2"] );
  
  //output: test3
  console.log( testNode.className );
  
  </script>
  ```