'test selection fields'

def test_22_selection(self):

    record = self.env['test_new_api.mixed'].create({})
    record.lang = None
    self.assertFalse(record.lang)
    for language in self.env['res.lang'].search([]):
        record.lang = language.code
    with self.assertRaises(ValueError):
        record.lang = 'zz_ZZ'
