@Test
public void testGetParentsOfSet() {

  //id3-> id5, id4->id5
  Set<TermId> queryTerms = ImmutableSet.of(id3, id4);
  Set<TermId> expected = ImmutableSet.of(id3, id4, id5);
  assertEquals(expected, getParentTerms(ontology, queryTerms));
}