static async loginUser(user) {

  try {

    const { email, password } = user;

    // Retrieve the user with the provided email from the data store

    const existingUser = await users.findOne({ email });

    // Check if the user exists

    if (!existingUser) {

      return { error: 'User not found' };

    }

    // Compare the provided password with the stored password hash

    const isPasswordValid = await bcrypt.compare(password, existingUser.password);

    // Check if the password is valid

    if (!isPasswordValid) {

      return { error: 'Invalid password' };

    }

    // Generate a token or session for the authenticated user

    const token = generateToken(existingUser);

    // Return the token or any other relevant information

    return { token: token };

  } catch (e) {

    console.error(`Unable to login user: ${e}`);

    return { error: e };

  }

}