How to split the validation.yml file

AcmeBlogExtension.php

<?php

namespace Acme\BlogBundle\DependencyInjection;

use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
use Symfony\Component\HttpKernel\DependencyInjection\Extension;
use Symfony\Component\Config\FileLocator;

class AcmeBlogExtension extends Extension
{
    public function load(array $configs, ContainerBuilder $container)
    {   
        $loader = new YamlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
        $loader->load('services.yml');
        $loader->load('listeners.yml');

        $this->loadValidationConfiguration($container);
    }   

    protected function loadValidationConfiguration(ContainerBuilder $container)
    {   
        $yamlMappingFiles = $container->getParameter('validator.mapping.loader.yaml_files_loader.mapping_files');
        $yamlMappingFiles[] = __DIR__.'/../Resources/config/validation/Post.yml';
        $yamlMappingFiles[] = __DIR__.'/../Resources/config/validation/Comment.yml';

        $container->setParameter('validator.mapping.loader.yaml_files_loader.mapping_files', $yamlMappingFiles);
    }   
}

Comment.yml

Acme\BlogBundle\Entity\Comment
    properties:
        username:
            - NotBlank:  ~
            - MaxLength: 50
        email:
            - Email:     ~
        comment:
            - NotBlank:  ~
            - MinLength: 50

Post.yml

Acme\BlogBundle\Entity\Post:
    properties:
        title:
            - NotBlank: ~
        body:
            - MinLength: 50

validation.yml

Acme\BlogBundle\Entity\Comment
    properties:
        username:
            - NotBlank:  ~
            - MaxLength: 50
        email:
            - Email:     ~
        comment:
            - NotBlank:  ~
            - MinLength: 50

Acme\BlogBundle\Entity\Post:
    properties:
        title:
            - NotBlank: ~
        body:
            - MinLength: 50