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

async function createEncodedCiphertext(
  preKey,
  text = 'Hello, World!',
  receivingIdentity = TestFactory.cryptography_repository.cryptobox.identity,
) {
  const bobEngine = new MemoryEngine();
  await bobEngine.init('bob');

  const sender = new Cryptobox(bobEngine, 1);
  await sender.create();

  const genericMessage = new GenericMessage({
    [GENERIC_MESSAGE_TYPE.TEXT]: new Text({content: text}),
    messageId: createRandomUuid(),
  });

  const sessionId = `from-${sender.identity.public_key.fingerprint()}-to-${preKey.key_pair.public_key.fingerprint()}`;
  const preKeyBundle = Proteus.keys.PreKeyBundle.new(receivingIdentity.public_key, preKey);

  const cipherText = await sender.encrypt(
    sessionId,
    GenericMessage.encode(genericMessage).finish(),
    preKeyBundle.serialise(),
  );

  return arrayToBase64(cipherText);
}

it('can map a text wrapped inside an external message', async () => {
      const plaintext = 'Test';
      const text = new Text({content: plaintext});
      const generic_message = new GenericMessage({
        [GENERIC_MESSAGE_TYPE.TEXT]: text,
        messageId: createRandomUuid(),
      });

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

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

.then(() => {
          const text = new Text({
            content:
              'massive external message massive external message massive external message massive external message massive external message massive external message massive external message massive external message massive external messagemassive external message massive external message massive external message massive external message massive external message massive external message massive external message massive external message massive external messagemassive external message massive external message massive external message massive external message massive external message massive external message massive external message massive external message massive external messagemassive external message massive external message massive external message massive external message massive external message massive external message massive external message massive external message massive external message',
          });
          const genericMessage = new GenericMessage({
            [GENERIC_MESSAGE_TYPE.TEXT]: text,
            messageId: createRandomUuid(),
          });

          const eventInfoEntity = new EventInfoEntity(genericMessage, largeConversationEntity.id);
          return TestFactory.conversation_repository._shouldSendAsExternal(eventInfoEntity);
        })
        .then(shouldSendAsExternal => {