def to_cloudformation(self, **kwargs):
function = kwargs.get('<STR_LIT>')<EOL>if not function:<EOL><INDENT>raise TypeError("<STR_LIT>")<EOL><DEDENT>return [self._construct_permission(function, source_arn=self.Topic),<EOL>self._inject_subscription(function, self.Topic, self.FilterPolicy)]<EOL>
Returns the Lambda Permission resource allowing SNS to invoke the function this event source triggers.

        :param dict kwargs: no existing resources need to be modified
        :returns: a list of vanilla CloudFormation Resources, to which this SNS event expands
        :rtype: list