I would like to verify that the objects in the following array:

```
const payment1: Payment = new Payment('1000'); // 1000 = id
const payment2: Payment = new Payment('1001');

const paymentArray: Payment[];
paymentArray.push(payment1, payment2);

```

exist in my observable array:

```
payments$: Observable<Payment[]>;

```

What i would like is to get a non observable boolean as result. 

I have tried somethings with filter pipe and map but unfortunately cant get it to work:

```
this.paymentArray.forEach(element => {
  this.payments$.pipe(map(payments => payments.filter(payment => payment.id === element['id'])));
});

```