'Test tuples with null and empty string fields.'

def test_can_insert_tuples_with_nulls(self):

    if (self.cass_version < (2, 1, 0)):
        raise unittest.SkipTest('The    tuple    type    was    introduced    in    Cassandra    2.1')
    s = self.session
    s.execute('CREATE    TABLE    tuples_nulls    (k    int    PRIMARY    KEY,    t    frozen<tuple<text,    int,    uuid,    blob>>)')
    insert = s.prepare('INSERT    INTO    tuples_nulls    (k,    t)    VALUES    (0,    ?)')
    s.execute(insert, [(None, None, None, None)])
    result = s.execute('SELECT    *    FROM    tuples_nulls    WHERE    k=0')
    self.assertEqual((None, None, None, None), result[0].t)
    read = s.prepare('SELECT    *    FROM    tuples_nulls    WHERE    k=0')
    self.assertEqual((None, None, None, None), s.execute(read)[0].t)
    s.execute(insert, [('', None, None, '')])
    result = s.execute('SELECT    *    FROM    tuples_nulls    WHERE    k=0')
    self.assertEqual(('', None, None, ''), result[0].t)
    self.assertEqual(('', None, None, ''), s.execute(read)[0].t)
