rtm-ctrlz

/**
 * Initializes a socket server for HMR for webpack-dev-server.
 * @param {function(*): void} messageHandler A handler to consume Webpack compilation messages.
 * @returns {void}
 */
function initWDSSocket(messageHandler) {
  let SockJSClient;
  try {
      // that still produces compilation warning
      ({ default: SockJSClient } = require('webpack-dev-server/client/clients/SockJSClient'));