vertx / io.vertx.reactivex.core.http / ServerWebSocket / writePong

# writePong

`open fun writePong(data: Buffer): WebSocketBase`

Overrides WebSocketBase.writePong

Writes a pong to the connection. This will be written in a single frame. Pong frames may be at most 125 bytes (octets).

This method should not be used to write application data and should only be used for implementing a keep alive or to ensure the client is still responsive, see RFC 6455 Section 5.5.2.

There is no need to manually write a Pong, as the server and client both handle responding to a ping with a pong automatically and this is exposed to users.RFC 6455 Section 5.5.3 states that pongs may be sent unsolicited in order to implement a one way heartbeat.

### Parameters

`data` - the data to write, may be at most 125 bytes

Return
a reference to this, so the API can be used fluently