     }
      }
    };

    stash.receive().then(data => {
      testCase = data;

      // PresentationConnection_send-manual.https.html
      if (testCase === 'send') {
        stash.send('ok');
      }
      // PresentationConnection_onmessage-manual.https.html
      else if (testCase === 'onmessage') {
        connection.send(message1);              // string
        connection.send(message2);              // string
        connection.send(new Blob([message3]));  // Blob
        connection.send(message4.