def resources_removed(resources)
      if resources.kind_of?(Enumerable)
        resources.each { |resource| resource_removed(resource) }
      else
        resource_removed(resources)
      end
    end
def resources_removed(resources)
      if resources.kind_of?(Enumerable)
        resources.each { |resource| resource_removed(resource) }
      else
        resource_removed(resources)
      end
    end
Track the removed resources

 @param [Array<Resource>] resources
   the resources that were removed

 @return [Array<Resource>]
   the resources that were removed

 @api private