UserName example

$this->validator = $validator;
    }

    /** * @throws ValidationException */
    public function validate(User $user)
    {
        $this->validationContext = $this->validator->startContext();

        $this->validateField('username', $user->getUsername(), [
            new UserName([
                'userId' => $user->getId(),
            ]),
            new NoUrl(),
        ]);
        $this->validateField('name', $user->getName(), [new NotBlank(), new NoUrl()]);
        $this->validateField('role', $user->getRole(), [new NotBlank()]);
        $this->validateField('email', $user->getEmail(), [
            new UserEmail([
                'userId' => $user->getId(),
            ]),
        ]);