connect: async (url, schema, modelName, key, dbOptions, schemaOptions, algorithm) => {
    if (algorithm) setAlgorithm(algorithm);
    if (!key) throw new PersonalDataStorageError("Key must not be undefined!");
    setKey(key);
    await generateModel(schema, modelName, schemaOptions);
    await connect(url, dbOptions);
    return setIndexSettings(schema, dbOptions, key);
  },

  close: () => {
    disconnect();
  },

  isConnected: () => {
    return getConnect();
  },

  upsert: async (data, opts) => {
    if (!getConnect()) throw new PersonalDataStorageError("No connection to MongoDb!");
    if (opts && typeof opts !== "object"){
      console.log("\x1b[33m%s\x1b[0m","\n[personal-data-storage] - WARNING - options must be as object. Applied options by default\n");
      opts = undefined;
    }
    deleteUndefinedKey(data);
    if (!data) throw new PersonalDataStorageError("No data for upsert");
    await validateData(data);
    return data.id ? update(data.id, data, opts) : insert(data, opts); // promise
  },

  get: async (id) => {
    if (!id) throw new PersonalDataStorageError("No id to find");
    if (!getConnect()) throw new PersonalDataStorageError("No connection to MongoDb!");
    if (!ObjectId.isValid(id)) throw new PersonalDataStorageError("id is not ObjectId!", 400);
    return getDataByID(id); //promise
  },

  find: async (key, value) => {
    if (!key) throw new PersonalDataStorageError("No key to find");
    if (!value) throw new PersonalDataStorageError("No value to find");
    return find(key, value); //promise
  },

  delete: async (id) => {
    if (!id) throw new PersonalDataStorageError("No id to delete");
    if (!getConnect()) throw new PersonalDataStorageError("No connection to MongoDb!");
    if (!ObjectId.isValid(id)) throw new PersonalDataStorageError("id is not ObjectId!", 400);
    return deleteById(id); //promise
  },

  startTransaction: () => {
    return new Promise(async (resolve, reject) => {
      const session = await getModel().startSession();
      session.startTransaction();
      resolve(session);
    });
  },

  commitTransaction: (session) => {
    return new Promise(async (resolve, reject) => {
      await session.commitTransaction();
      session.endSession();
      resolve();
    });
  },

  abortTransaction: (session) => {
    return new Promise(async (resolve, reject) => {
      await session.abortTransaction();
      session.endSession();
      resolve();
    });
  }