Question: how to override itemOperations.get

[wow-apps]

Can someone help me to override GET method with default path.

What I need:
GET /api/content_pages/{id} should use my custom controller, where I need to return result using header Accept-Language

// config/api/content_page.yaml
resources:
  Api\Entity\ContentPage:
    itemOperations:
      get:
        route_name: 'get_content_page'
        methods: ['GET']
        normalization_context:
          groups: ['v1_get_item']
        swagger_context:
          parameters:
            -
              name: id
              in: path
              required: true
              type: string
              description: "Content page identifier"

// config/routes.yaml
get_content_page:
  path: /content_pages/{id}
  methods: ['GET']
  condition: "request.headers.get('Accept-Language') matches '/^[a-z]{2}-[A-Z]{2}$/i'"
  defaults:
    _controller: Api\Controller\ContentPagesController::getContentPage
    _api_resource_class: Api\Entity\ContentPage
    _api_item_operation_name: get

?php
// src/Controller/ContentPagesController.php
namespace Api\Controller;
use Api\Entity\ContentPage;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Request;
class ContentPagesController extends AbstractController
{
    /**
     * @param Request $request
     * @param string  $id
     * @return ContentPage
     */
    public function getContentPage(Request $request, string $id): ContentPage
    {
        dd($request->headers->get('Accept-Language'));
    }
}

I'm getting No route found for \"GET \/content_pages\/about\": Method Not Allowed (Allow: PUT, DELETE)

If, I do next change:

// config/api/content_page.yaml
resources:
  Api\Entity\ContentPage:
    itemOperations:
      get: ~
      get_item:
        route_name: 'get_content_page'
        methods: ['GET']
        normalization_context:
          groups: ['v1_get_item']
        swagger_context:
          parameters:
            -
              name: id
              in: path
              required: true
              type: string
              description: "Content page identifier"

I get Invalid identifier value or configuration.

[wow-apps]

Problem was in condition: "request.headers.get('Accept-Language') matches '/^[a-z]{2}-[A-Z]{2}$/i'" .... trying to figure out solution...