Create an event in the backend to be triggered given a circumstance.

        :param request_id: Request ID of a involved session.
        :param trigger: Circumstance that will trigger the event.
        :param event: Reason of the message that will be created.
        :param message: Content of the message that will be created.

def event(self, request_id, trigger, event, message):
        """Create an event in the backend to be triggered given a circumstance.

        :param request_id: Request ID of a involved session.
        :param trigger: Circumstance that will trigger the event.
        :param event: Reason of the message that will be created.
        :param message: Content of the message that will be created.
        """
        self.connection.send({
            'reason': ['request', 'event'],
            'request_id': request_id,
            'content': {
                'trigger': trigger,
                'message': {
                    'reason': event,
                    'content': message,
                },
            },
        })