def test_with_spaces(self):
     self.assertEqual('ABC123', normalize_plate_number('ABC 123'))
 def test_case_sensitivity(self):
     self.assertEqual(normalize_plate_number('abc123'),
                      normalize_plate_number('ABC123'))
 def test_with_lower_and_hyphens(self):
     self.assertEqual('ABC123', normalize_plate_number('abc-123'))
 def test_with_mixed_case_and_hyphens(self):
     self.assertEqual('ABC123', normalize_plate_number('AbC-123'))
 def test_with_hyphens(self):
     self.assertEqual('ABC123', normalize_plate_number('ABC-_-123'))