public String getHash() {
        return hash;
    }
@Test
    public void schemaHashTest() {
        SimpleHollowDataset dataset = SimpleHollowDataset.fromClassDefinitions(Long.class, Movie.class);
        HollowReadStateEngine readState = new HollowReadStateEngineBuilder(Arrays.asList(Long.class, Movie.class)).build();

        HollowSchemaHash hollowSchemaHash1 = new HollowSchemaHash(dataset.getSchemas());
        HollowSchemaHash hollowSchemaHash2 = new HollowSchemaHash(readState.getSchemas());

        assertEquals(hollowSchemaHash1, hollowSchemaHash2);
        assertNotNull(hollowSchemaHash1.getHash());
        assertNotEquals("", hollowSchemaHash1.getHash());
    }