Rx\Subject\BehaviorSubjectTest::it_exposes_if_it_has_observers PHP Method

    public function it_exposes_if_it_has_observers()
    {
        $subject = new BehaviorSubject();
        $this->assertFalse($subject->hasObservers());
        $observer = $this->createMock('Rx\\ObserverInterface');
        $subject->subscribe($observer);
        $this->assertTrue($subject->hasObservers());
    }