@Override
    public List<String> listDbNames() {
        return deltaOps.getAllDatabaseNames();
    }
@Test
    public void testListDbNames() {
        List<String> dbNames = deltaLakeMetadata.listDbNames();
        Assert.assertEquals(2, dbNames.size());
        Assert.assertEquals("db1", dbNames.get(0));
        Assert.assertEquals("db2", dbNames.get(1));
    }