code: def poll(self, authzr):
          
          action = LOG_ACME_POLL_AUTHORIZATION(authorization=authzr)
          with action.context():
              return (
                  DeferredContext(self._client.get(authzr.uri))
                  # Spec says we should get 202 while pending, Boulder actually
                  # sends us 200 always, so just don't check.
                  # .addCallback(self._expect_response, http.ACCEPTED)
                  .addCallback(
                      lambda res:
                      self._parse_authorization(res, uri=authzr.uri)
                      .addCallback(
                          self._check_authorization, authzr.body.identifier)
                      .addCallback(
                          lambda authzr:
                          (authzr,
                           self.retry_after(res, _now=self._clock.seconds)))
                  )
                  .addCallback(tap(
                      lambda a_r: action.add_success_fields(
                          authorization=a_r[0], retry_after=a_r[1])))
                  .addActionFinish())
docs: Update an authorization from the server (usually to check its status).