Artist memberB = ArtistImpl.create("MemberB", sourceMock);
((GroupArtist) group).addArtist(memberA);
((GroupArtist) group).addArtist(memberB);
Track trackMockA = EasyMock.createMock(Track.class);
group.addTrack(trackMockA);
assertTrue(group.getTracks().contains(trackMockA));
assertTrue(memberA.getTracks().contains(trackMockA));
assertTrue(memberB.getTracks().contains(trackMockA));
Track trackMockB = EasyMock.createMock(Track.class);
group.addTrackAsComposer(trackMockB);
assertTrue(group.getTracksAsComposer().contains(trackMockB));
assertTrue(memberA.getTracksAsComposer().contains(trackMockB));
assertTrue(memberB.getTracksAsComposer().contains(trackMockB));