Function ping

ping(websocketAlias?): Promise<void | Error>
Send WebSocket PING to server.
Parameters
- websocketAlias: string = "standard"
  
  WebSocket alias, otherwise the default alias is used.
Returns Promise<void | Error>
Promise, is resolved if the server responds with a PONG, otherwise it will be rejected.
Note
The session is going to be refreshed.

Example
```
ix.api.websocket.ping();
```