async def on_ping(self, sid: str):
        """Event for testing the API endpoint.

        Args:
            sid: The Socket.IO session id.
        """
        # Emit the test event.
        await self.emit(str(constants.SocketEvent.PING), "pong", to=sid)
Event for testing the API endpoint.

        Args:
            sid: The Socket.IO session id.
        
reflex/app.py