public function testApproveUpdatesStateAndFiresEvent()
 {
     $series = new ExistingReservationSeries();
     $series->WithStatus(ReservationStatus::Pending);
     $series->Approve($this->fakeUser);
     $events = $series->GetEvents();
     $this->assertEquals(ReservationStatus::Created, $series->StatusId());
     $this->assertTrue(in_array(new SeriesApprovedEvent($series), $events));
 }