code: def dismiss(self, message):
          
          assert isinstance(message, (str, unicode)), message
          post_parameters = {'message': message}
          headers, data = self._requester.requestJsonAndCheck(
              "PUT",
              self.pull_request_url + "/reviews/%s/dismissals" % self.id,
              input=post_parameters
          )
docs: :calls: `PUT /repos/:owner/:repo/pulls/:number/reviews/:review_id/dismissals <https://developer.github.com/v3/pulls/reviews/>`_
          :rtype: None