def METHOD_NAME(check_error_response, both_clients):
    """Using a parameter without equality sign `=` or values should result in a `400 Bad Request` response"""
    from optimade.server.query_params import EntryListingQueryParams
    with pytest.warns(FieldValueNotRecognized):
        for valid_query_parameter in EntryListingQueryParams().__dict__:
            request = f"/structures?{valid_query_parameter}"
            with pytest.raises(BadRequest):
                check_error_response(
                    request,
                    expected_status=400,
                    expected_title="Bad Request",
                    expected_detail="A query parameter without an equal sign (=) is not supported by this server",
                    server=both_clients,
                )