def delete_activities_for_entity_model(model)
      Activr.registry.activity_entities_for_model(model.class).each do |entity_name|
        self.driver.delete_activities(:entities => { entity_name => model.id })
      end
    end
def delete_activities_for_entity_model(model)
      Activr.registry.activity_entities_for_model(model.class).each do |entity_name|
        self.driver.delete_activities(:entities => { entity_name => model.id })
      end
    end
Delete activities referring to given entity model instance

 @param model [Object] Model instance