Bad ID on custom LDPViewSet

When defining a custom LDPViewSet, the ID of the retrieved document is wrong.

for instance :

GET http://localhost:8000/sources/dvsd/

returns :

{
  "@id": "http://localhost:8000/sources/", 
  "@type": "ldp:Container",
  "ldp:contains": [],
  "permissions": [
    {
      "mode": {
        "@type": "view"
      }
    }
  ],
  "@context": "https://cdn.happy-dev.fr/owl/hdcontext.jsonld"
}

@id should be : http://localhost:8000/dvsd/