How to use the dictdiffer.utils.WildcardDict function in dictdiffer

def test_wildcarddict(self):
        wd = WildcardDict()

        wd[('authors', '*')] = True

        self.assertRaises(KeyError, wd.__getitem__, ('authors',))
        self.assertTrue(wd[('authors', 1)])
        self.assertTrue(wd[('authors', 1, 'name')])
        self.assertTrue(wd[('authors', 1, 'affiliation')])

        del wd[('authors', '*')]

        wd[('authors', '+')] = True

        self.assertRaises(KeyError, wd.__getitem__, ('authors',))
        self.assertTrue(wd[('authors', 1)])
        self.assertRaises(KeyError, wd.__getitem__, ('authors', 1, 'name'))
        self.assertRaises(KeyError, wd.__getitem__, ('authors', 1,

self.assertRaises(KeyError, wd.__getitem__, ('authors',))
        self.assertTrue(wd[('authors', 1)])
        self.assertRaises(KeyError, wd.__getitem__, ('authors', 1, 'name'))
        self.assertRaises(KeyError, wd.__getitem__, ('authors', 1,
                                                     'affiliation'))

        del wd[('authors', '+')]

        wd[('foo', 'bar')] = True

        self.assertRaises(KeyError, wd.__getitem__, ('foo',))
        self.assertTrue(wd[('foo', 'bar')])
        self.assertRaises(KeyError, wd.__getitem__, ('foo', 'bar', 'banana'))

        # query_path part
        wd = WildcardDict()
        wd[('authors', '*')] = True
        wd[('apple', '+')] = True
        wd[('foo', 'bar')] = True

        self.assertRaises(KeyError, wd.query_path, ('utz',))
        self.assertRaises(KeyError, wd.query_path, ('foo',))
        self.assertRaises(KeyError, wd.query_path, ('bar',))
        self.assertRaises(KeyError, wd.query_path, ('apple', 'banana',
                                                    'mango'))
        self.assertEqual(('authors', '*'), wd.query_path(('authors', 1)))
        self.assertEqual(('authors', '*'), wd.query_path(('authors', 1, 1)))
        self.assertEqual(('authors', '*'), wd.query_path(('authors', 1, 1, 1)))
        self.assertEqual(('apple', '+'), wd.query_path(('apple', 'banana')))
        self.assertEqual(('apple', '+'), wd.query_path(('apple', 'mango')))
        self.assertEqual(('foo', 'bar'), wd.query_path(('foo', 'bar')))

>>> w[ ('foo', 'bar') ]
            '* card'
            >>> w[ ('foo', 'bar', 'baz') ]
            '* card'
            >>> w[ ('banana', 'apple') ]
            '+ card'
            >>> w[ ('banana', 'apple', 'mango') ]
            Traceback (most recent call last):
                ...
            KeyError
        """
        try:
            return super(WildcardDict, self).__getitem__(key)
        except KeyError:
            if key[:-1] in self.plus_keys:
                return super(WildcardDict, self).__getitem__(key[:-1]+('+',))
            for _key in [key[:-i] for i in range(1, len(key)+1)]:
                if _key in self.star_keys:
                    return super(WildcardDict, self).__getitem__(_key+('*',))
            raise KeyError