code: function initDomHandler(instance) {
      zrUtil.each(touchHandlerNames, function (name) {
          instance._handlers[name] = zrUtil.bind(domHandlers[name], instance);
      });
  
      zrUtil.each(pointerHandlerNames, function (name) {
          instance._handlers[name] = zrUtil.bind(domHandlers[name], instance);
      });
  
      zrUtil.each(mouseHandlerNames, function (name) {
          instance._handlers[name] = makeMouseHandler(domHandlers[name], instance);
      });
  
      function makeMouseHandler(fn, instance) {
          return function () {
              if (instance._touching) {
                  return;
              }
              return fn.apply(instance, arguments);
          };
      }
  }
docs: 为控制类实例初始化dom 事件处理函数
  
  @inner
  @param {module:zrender/Handler} instance 控制类实例