anchor.diff:    //SyntaxError: "0"-prefixed octal literals and octal escape sequences are deprecated; for octal literals use the "0o" prefix instead
   
     replButton.click(() => {
  +    createTerminalIn('repl-terminal-container');
       if (socket !== null) {
         socket.close();
         socket = null;
  
positive.code:     this.socket.onclose = function(event) {
        console.log('socket closed');
        terminal.detach(that.socket);
  
        // If the close corresponds to nginx timing out the socket, then
        // restart it silently.
        if (event.code == 1006) {
          that.start(url, terminal);
        }
      };
  
negative.code: 'use strict';
  $(() => {
  
    //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    function SocketMonitor(url, terminal) {
      // SocketMonitor watches the websocket
      // we use to talk to the server.
      // If it goes down outside of our control
      // it silently re-opens the socket.
      this.socket = null;
      this.start(url, terminal);
    };
  