Solution

import { Observable } from 'rxjs';

const observable: Observable<number> = new Observable((observer) => {
  console.log('%cNew subscription created', 'background: #222; color: #bada55');
});

observable.subscribe();
observable.subscribe();

Let review the solution code above:

• First, we import the Observable class from the rxjs module.
• We create a new instance of the Observable class providing the subscriber function, which receives the Observer.
• For this example, we simply log out that a new subscription has been created.
• We then subscribe to the Observable multiple times.
• Note that we should see two logs in our console, one for each subscriber.