def test_fuzz_filter_all_characters(self, filter: str):
        """
        Fuzz test filter string parsing invariants
        Testing random strings to ensure no error is raised with filters.
        Ensure no error is raised.
        TODO: Add coverage for equality, range, and IN filters with these random characters.
        Note that tokens with unescaped special characters will raise filter string parsing errors.
        """
        for index in [self.unstructured_default_text_index, self.structured_default_text_index]:
            with self.subTest(index=index.type):
                res = tensor_search.search(
                    text='', config=self.config, index_name=index.name,
                    filter=filter
                )
                self.assertIn("hits", res)

        Fuzz test filter string parsing invariants
        Testing random strings to ensure no error is raised with filters.
        Ensure no error is raised.
        TODO: Add coverage for equality, range, and IN filters with these random characters.
        Note that tokens with unescaped special characters will raise filter string parsing errors.
        
tests/integ_tests/tensor_search/integ_tests/test_search_combined.py