事件：'ping'

¥Event: 'ping'

• payload <Buffer> PING 帧 8 字节有效载荷

  ¥payload <Buffer> The PING frame 8-byte payload

每当从连接的对等方接收到 PING 帧时，则会触发 'ping' 事件。

¥The 'ping' event is emitted whenever a PING frame is received from the connected peer.