I **really** an imported 3rd party script to trigger a function like `show_end_screen` (below)

my component

```
import { Router } from '@angular/router';
import { init_game, start_game, stop_game } from '../../assets/js/game';

@Component({})

export class PlayComponent implements OnInit {
    constructor(public router:Router) {}
    ngOnInit() {
        init_game(this.show_end_screen) // load ready
    }
    show_end_screen(data){
        console.log(data) //this works
        this.router.navigate(['play']); //"this" is undefined
    }
}

```

`init_game(this.show_end_screen)` <== Here I am passing `show_end_screen` to the imported script. when the 3rd party script runs `show_end_screen(data)` I successfully log `data` to the console. But i dont have access to `this` or any other reference to angular

`this.router.navigate(['play']);` <== here i get a console error 

`ERROR TypeError: Cannot read property 'nav' of undefined`