code: def update_dispute(self, idempotency_key=None, **params):
          
          url = self.instance_url() + '/dispute'
          headers = populate_headers(idempotency_key)
          d = self.request('post', url, params, headers)
          d.addCallback(lambda response: self.refresh_from(
              {'dispute': response}, api_key, True))
          return d.addCallback(lambda _: self.dispute)
docs: Return a deferred.