I am learning reactJs, after reading this part of the docs:

> 
> An easy migration strategy for anyone upgrading their code to avoid
>  isMounted() is to track the mounted status yourself. Just set a
>  \_isMounted property to true in componentDidMount and set it to false in componentWillUnmount, and use this variable to check your
>  component's status.
> 
> 
> 

Does that mean the `_isMounted` value has to be stored in `state`?

I have this so far:

```
isMounted: function(){
    this.setState({ _isMounted: true });
},

componentDidMount: function() {
    if(this.state._isMounted) {  // This is bad.
        this.setState({...});
    }
},

```