method Transmitter.prototype.startHeartbeatimport { Transmitter } from "https://deno.land/x/sockets@v0.5.0/mod.ts"; startHeartbeat(clientId: number): numberStart a heartbeat for the client in question. ParametersclientId: number The WebSocket connection ID of the client in question. ReturnsnumberThe heartbeat ID. This is used to clear a heartbeat in timeoutPing().