Scrobble scrobble2 = new Scrobble(user1, track1, false);
Message message1 = new GenericMessage<Scrobble>(scrobble1);
Message message2 = new GenericMessage<Scrobble>(scrobble2);
PollableChannel scrobbleChannel = mock(PollableChannel.class);
when(scrobbleChannel.receive()).thenReturn(message1, message2, null);
scrobbleService.setScrobbleChannel(scrobbleChannel);
scrobbleService.receive();
assertNotNull(scrobbleService.userScrobbles);