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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_runtime_attr(self, attr_name):
 """ 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 """


        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)