def test_true_2(self): self.assertTrue(double_check('a 11 c d'))
def test_true(self): self.assertTrue(double_check('aabc'))
def test_false(self): self.assertFalse(double_check('abca'))
def test_false_2(self): self.assertFalse(double_check('a b c d e f g h i h k'))
def test_true_3(self): self.assertTrue(double_check('AabBcC'))