// Send confirmation email when emailConfirmationToken is created or updated
  $subscribe
    .userSecurity({
      mutation_in: ['UPDATED'],
      updatedFields_contains: 'emailConfirmationToken',
    })
    .node()
    .user()
    .then(async (iterator) => {
      while (true) {
        const result = await iterator.next();

        const userService = ioc.get<IUserService>(Services.UserService);
        const userId = result.value.id;
        const user = await userService.getUserById(userId);

        if (!user.security.emailConfirmationToken) { continue; }

        const emailText = `
        Your email confirmation token is ${user.security.emailConfirmationToken}
      `;
        emailService.sendMessage(user.email, 'Email confirmation', emailText);
      }
    });