@Test
public void testCreateCommitWithOnlyAuxiliary() {

    //Setup:
    InProgressCommit inProgressCommit = inProgressCommitFactory.createNew(IN_PROGRESS_COMMIT_IRI);
    Commit auxiliary = commitFactory.createNew(COMMIT_IRI);
    thrown.expect(IllegalArgumentException.class);
    thrown.expectMessage("Commit must have a base commit in order to have an auxiliary commit");
    manager.createCommit(inProgressCommit, "message", null, auxiliary);
}