Symfony callback validator

CommandValidator.php

<?php

namespace Acme;

use Symfony\Component\Validator\Constraints\NotBlank;
use Symfony\Component\Validator\Context\ExecutionContextInterface;

class CommandValidator
{
    public static function validate($object, ExecutionContextInterface $context)
    {
        $notBlank = new NotBlank();
        $context->buildViolation($notBlank->message)
            ->atPath('realizationMethod')
            ->setCode('my_awesome_code
            ->addViolation()
        ;
    }
}

response_add.json

{  
   "errors":[  
      {  
         "code":"callback",
         "status":400,
         "title":"Ta wartość nie powinna być pusta.",
         "source":{  
            "pointer":"/data/attributes/realizationMethod"
         }
      }
   ],

}

response_remove.json

{  
   "errors":[  
      {  
         "code":"not_blank_is_blank_error",
         "status":400,
         "title":"Ta wartość nie powinna być pusta.",
         "source":{  
            "pointer":"/data/attributes/realizationMethod"
         }
      }
   ],

}

validator.yml

AddCommand:
  constraints:
    - Callback: [Acme\CommandValidator, validate]
   
RemoveCommand:
  properties:
    realizationMethod:
      - NotBlank: ~