I'm using the react-google-maps library for a project and i found a perfect example for what i need. It is the code below and as you can see it is a class component. 
class Map extends Component {
  constructor(props){
    super(props);
    this.map = React.createRef();
  }
  render() {
    const MyGoogleMap = withScriptjs(
      withGoogleMap(props => (
        <GoogleMap
          ref={map => {
            this.map = map;
          }}
        />
      ))
    );
    return(
      <MyGoogleMap />
    );
  }
}
export default Map
I want to migrate this class in a function component.
The lines i don't know how to implement to a function components is
this.map = React.createRef();
and
ref={map => { this.map = map }}
 
    