CreateAUserHandler.php

<?php

namespace App\Domain;

final class CreateAUserHandler
{
    private UserRepositoryInterface $userRepository;

    public function __construct(UserRepositoryInterface $userRepository)
    {
        $this->userRepository = $userRepository;
    }

    public function execute(CreateAUserInput $input): CreateAUserOutput
    {
        $user = User::create(
            $input->getName(),
            $input->getAge()
        );
        
        $this->userRepository->save($user);

        return new CreateAUserOutput(
            $user->getUserId()->getId(),
            $user->getName(),
            $user->getAge()
            );
    }
}