'Return the given message.'

@wsgi.Controller.api_version(MESSAGES_BASE_MICRO_VERSION)
def show(self, req, id):

    context = req.environ['cinder.context']
    message = self.message_api.get(context, id)
    check_policy(context, 'get', message)
    self._build_user_message(message)
    return self._view_builder.detail(req, message)
