'has_key and __contains__'

def test_contains_has(self):

    test_son = SON([(1, 100), (2, 200), (3, 300)])
    self.assertIn(1, test_son)
    self.assertTrue((2 in test_son), 'in    failed')
    self.assertFalse((22 in test_son), "in    succeeded    when    it    shouldn't")
    self.assertTrue(test_son.has_key(2), 'has_key    failed')
    self.assertFalse(test_son.has_key(22), "has_key    succeeded    when    it    shouldn't")
