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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_resource_scenario(resource_attr_id, scenario_id, **kwargs):
 """ Get the resource scenario object for a given resource atttribute and scenario. This is done when you know the attribute, resource and scenario and want to get the value associated with it. """

    user_id = kwargs.get('user_id')

    _get_scenario(scenario_id, user_id)

    try:
        rs = db.DBSession.query(ResourceScenario).filter(ResourceScenario.resource_attr_id==resource_attr_id,
                                             ResourceScenario.scenario_id == scenario_id).options(joinedload_all('dataset')).options(joinedload_all('dataset.metadata')).one()

        return rs
    except NoResultFound:
        raise ResourceNotFoundError("resource scenario for %s not found in scenario %s"%(resource_attr_id, scenario_id))