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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 set_resource_attribute(self, attr, value):
 """Sets attributes on resource. Resource attributes are top-level entries of a CloudFormation resource that exist outside of the Properties dictionary :param attr: Attribute name :param value: Attribute value :return: None :raises KeyError if `attr` is not in the supported attribute list """


        if attr not in self._supported_resource_attributes:
            raise KeyError("Unsupported resource attribute specified: %s" % attr)

        self.resource_attributes[attr] = value