class Test
{
    public function __construct(
        public mixed $test,
    ) {
    }
}

class Test
{
    public function __construct(
        private mixed $test,
    ) {
    }

    public function getTest(): mixed
    {
        return $this->test;
    }
}

$userAvatarDto = $serializer->deserialize(
    $content,
    UserAvatarDto::class,
    'json'
);

class UserAvatarDto
{
    #[Assert\Sequentially([
        new Assert\NotBlank(
            allowNull: true,
            message: HttpErrorMessage::USER_EDITION_AVATAR_MISSING->value,
            normalizer: 'trim'
        ),
        new Assert\Type('string', message: HttpErrorMessage::USER_EDITION_AVATAR_WRONG_FORMAT->value),
    ])]
    private mixed $avatar = null;

    /**
     * Get the value of avatar.
     */
    public function getAvatar(): mixed
    {
        return $this->avatar;
    }

    /**
     * Set the value of avatar.
     */
    public function setAvatar(mixed $avatar): self
    {
        $this->avatar = $avatar;

        return $this;
    }
}