anchor.diff:  <button type="button" id="repl-button" title="starts a REPL">repl</button>
  +
  +<div id="repl-box"></div>
   
   <script type="text/javascript">
   'use strict';
  
positive.code:           f();
          }
        };
      };
  
      // container[0] must already be visible
      const terminal = createTerminalIn(container[0]);
  
      createRepl(terminal).then(() => {
        const socket = new SocketMonitor(socketUrl, terminal);
  
negative.code:     Terminal.applyAddon(fullscreen);
      Terminal.applyAddon(search);
      Terminal.applyAddon(winptyCompat);
      terminal.open(container);
      terminal.winptyCompatInit();
      terminal.fit();
      terminal.focus();
  