element-ui el-tree 点击节点事件如何获取事件源?

Question

因为firefox不支持window.event 通常的解决方法var evt = window.event || arguments.callee.caller.arguments[0]在严格模式下会报Uncaught TypeError: 'caller', 'callee', and 'arguments' properties may not be accessed on strict mode functions or the arguments objects for calls to them

<el-tree :data="data" :props="defaultProps" @node-click="handleNodeClick"  node-key="id"></el-tree>

   handleNodeClick(node,data,value) {
            console.log(node)
            console.log(data)
            var myTarget = value.$el
            //console.log(value.$el)
            console.log(arguments.callee)
            let event = window.event || arguments.callee.caller.arguments[0];
            let target = event.srcElement||event.target;
        },

请问各位有什么其他的方法能够在firefox浏览器中获取到当前事件的事件源