@Test
public void acceptMergeRequestWithNoTargetHeadTest() {

    // Setup
    targetBranch1.removeProperty(targetCommit1.getResource(), VALUE_FACTORY.createIRI(Branch.head_IRI));
    thrown.expect(IllegalStateException.class);
    try (RepositoryConnection conn = repo.getConnection()) {
        manager.acceptMergeRequest(request1.getResource(), user1, conn);
    }
    verify(versioningManager, never()).merge(any(Resource.class), any(Resource.class), any(Resource.class), any(Resource.class), any(User.class), any(), any());
}