How to use the @wireapp/protocol-messaging.Knock function in @wireapp/protocol-messaging

it('can map a ping wrapped inside an external message', async () => {
      let external_message = undefined;

      const genericMessage = new GenericMessage({
        knock: new Knock({hotKnock: false}),
        messageId: createRandomUuid(),
      });

      const encryptedAsset = await encryptAesAsset(GenericMessage.encode(genericMessage).finish());
      const keyBytes = new Uint8Array(encryptedAsset.keyBytes);
      const sha256 = new Uint8Array(encryptedAsset.sha256);
      event.data.data = await arrayToBase64(encryptedAsset.cipherText);

      external_message = new GenericMessage({
        external: new External({otrKey: keyBytes, sha256}),
        messageId: createRandomUuid(),
      });
      const event_json = await mapper.mapGenericMessage(external_message, event);

      expect(isObject(event_json)).toBeTruthy();
      expect(event_json.type).toBe(ClientEvent.CONVERSATION.KNOCK);

it('maps legal hold states for ping messages', async () => {
      const expectedLegalHoldStatus = LegalHoldStatus.DISABLED;

      const optimisticEvent = {
        conversation: 'ecf815e4-ef9d-494c-827b-85214b9d694e',
        data: {},
        from: '90f56eae-ef65-4b49-9efb-2d6502721965',
        status: 1,
        time: '2019-07-10T15:08:24.751Z',
        type: 'conversation.message-add',
      };

      const protoKnock = new Knock({
        [PROTO_MESSAGE_TYPE.EXPECTS_READ_CONFIRMATION]: false,
        [PROTO_MESSAGE_TYPE.LEGAL_HOLD_STATUS]: expectedLegalHoldStatus,
        hotKnock: false,
      });

      const genericMessage = new GenericMessage({
        [GENERIC_MESSAGE_TYPE.KNOCK]: protoKnock,
        messageId: createRandomUuid(),
      });

      const mappedEvent = await mapper.mapGenericMessage(genericMessage, optimisticEvent);

      expect(mappedEvent.data.legal_hold_status).toBe(expectedLegalHoldStatus);
    });