async function sendMessageTest(
          expectedUrl, messageType = 'license-request') {
        await initAndAttach();
        await sendEncryptedEvent();

        const operation = shaka.util.AbortableOperation.completed({});
        fakeNetEngine.request.and.returnValue(operation);
        const message = new Uint8Array(0);
        session1.on['message'](
            {target: session1, message: message, messageType: messageType});

        expect(fakeNetEngine.request).toHaveBeenCalledWith(
            shaka.net.NetworkingEngine.RequestType.LICENSE,
            jasmine.objectContaining({
              uris: [expectedUrl],
              method: 'POST',
              body: message,
              licenseRequestType: messageType,
            }), jasmine.anything());
      }
@param {string=} expectedUrl
@param {string=} messageType
@return {!Promise}