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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 list_subscriptions(self, service):
 """Asks for a list of all subscribed accounts and devices, along with their statuses."""

        data = {
            'service': service,
        }
        return self._perform_post_request(self.list_subscriptions_endpoint, data, self.token_header)