final RevCommit c4 = geogig.command(CommitOp.class).setMessage("commit for " + idL1).call();
LogOp op = geogig.command(LogOp.class);
op.addCommit(c2.getId());
op.addCommit(c4.getId());
Iterator<RevCommit> iterator = op.call();
assertNotNull(iterator);
assertTrue(iterator.hasNext());
assertEquals(c4, iterator.next());
assertTrue(iterator.hasNext());
assertEquals(c3, iterator.next());