call ldp api with nested data without ldp:contains

   "@context":"http://owl.openinitiative.com/oicontext.jsonld",
   "@graph":[  
      {  
         "@id":"http://localhost:8000/messages/1/",
         "http://happy-dev.fr/owl/#text":"message 4"
      },
      {  
         "@id":"http://localhost:8000/messages/2/",
         "http://happy-dev.fr/owl/#text":"message 3"
      },
      {  
         "@id":"http://localhost:8000/threads/1/",
         "http://happy-dev.fr/owl/#message_set":[  
            {  
               "@id":"http://localhost:8000/messages/1/"
            },
            {  
               "@id":"http://localhost:8000/messages/2/"
            }
         ],
         "http://happy-dev.fr/owl/#text":"fil 1",
         "http://happy-dev.fr/owl/#title":"thread 2"
      }
   ]
}