human
Solve the following python programming problem given the following code:
def _validate_against_tween(request, response = None, path_pattern = '/', **overrides) : 
    '
    Acceptance testing helper for testing the swagger tween with Swagger 2.0
    responses.

    :param request: pyramid request
    :param response: standard fixture by default
    :param path_pattern: Path pattern eg. /foo/{bar}
    :param overrides: dict of overrides for `pyramid_swagger` config
    ' 
    def handler(request) : 
        return (response or Response ()) 
settings = dict ({ 
        'pyramid_swagger.schema_directory' : 'tests/sample_schemas/good_app/', 
        'pyramid_swagger.enable_swagger_spec_validation' : False, 
        'pyramid_swagger.enable_response_validation' : True, 
        'pyramid_swagger.swagger_versions' : ['2.0'], 
}, ** overrides) 
    spec = get_swagger_spec (settings) 
    settings ['pyramid_swagger.schema12'] = None 
    settings ['pyramid_swagger.schema20'] = spec 
    registry = get_registry (settings) 
    op = spec.get_op_for_request (request.method, path_pattern) 
    mock_route_info = { 
        'match' : request.matchdict, 
        'route' : None, 
} 
    mock_route_mapper = Mock (spec = IRoutesMapper, return_value = mock_route_info) 
    with patch ('pyramid_swagger.tween.get_op_for_request', return_value = op) : 
        with patch ('pyramid.registry.Registry.queryUtility', return_value = mock_route_mapper) : 
            validation_tween_factory (handler, registry) (op) 

    
    

    Fix the buggy line: validation_tween_factory (handler, registry) (op)
assistant
#Here is Python program to fix the buggy line: validation_tween_factory (handler, registry) (op)
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validation_tween_factory (handler, registry) (request)