message: avoid name collision
diff: @@ -150,12 +150,12 @@ for (let i = 0, ii = parts.length; i < ii; ++i) {
  }
  -function callCbOnDidOpenWebSocket(socket, cb) {
  +function callCbOnDidOpenWebSocket(sock, cb) {
  // check whether WebSocket is already open (readyState === 1).
  - if (socket.readyState === 1) {
  + if (sock.readyState === 1) {
  cb()
  } else {
  - socket.addEventListener('open', () => {
  + sock.addEventListener('open', () => {
  cb()
  }, {once: true})
  }
  