code: def get_runtime_attr(self, attr_name):
          
  
          if attr_name in self.runtime_attrs:
              return self.runtime_attrs[attr_name](self)
          else:
              raise NotImplementedError(attr_name + " attribute is not implemented for resource " + self.resource_type)
docs: Returns a CloudFormation construct that provides value for this attribute. If the resource does not provide
          this attribute, then this method raises an exception
  
          :return: Dictionary that will resolve to value of the attribute when CloudFormation stack update is executed