@Test
    void testDefaultIsUnionHostIndex() {
        IndexFacts.Session session = createIndexFacts().newSession(new Query());
        assertTrue(session.getIndex("c").isHostIndex());
        assertFalse(session.getIndex("a").isHostIndex());
    }
Tests using synthetic index names for IndexFacts class.

@author Steinar Knutsen
container-search/src/test/java/com/yahoo/prelude/test/IndexFactsTestCase.java