def clean_operations(operations):
    """Ensure that all parameters with "in" equal to "path" are also required
    as required by the Swagger specification.

    See https://github.com/swagger-api/swagger-spec/blob/master/versions/2.0.md#parameterObject.

    :param dict operations: Dict mapping status codes to operations
    """
    for operation in (operations or {}).values():
        for parameter in operation.get('parameters', []):
            if parameter['in'] == 'path':
                parameter['required'] = True
