Do I need to unsubscribe from subscriptions in my unit tests? : <p>If I have a test such as the following:</p>

<pre><code>it('should return some observable', async(() =&gt; {
  mockBackend.connections.subscribe((mockConnection: MockConnection) =&gt; {
    const responseOptions = new ResponseOptions({
      body: JSON.stringify(/* some response */)
    });

    mockConnection.mockRespond(new Response(responseOptions));
  });

  service.getSomeObservable()
    .subscribe(result =&gt; {
      expect(result).toBe(/* expected response */);
    });
}));
</code></pre>

<p>Do I need to unsubscribe from the subscription in an <code>afterEach</code> or <code>afterAll</code> block to avoid memory issues? Or will it be automatically removed?</p>
