solr nested schema

[sara hajili]

hi
i need add nested document in solr . how can i do this ?
how add nested document field in schema ?
for example i need to add this :
{
  "id":12,
   'topic":[ {
                   code:1,
                    name:"hi"
                },
                {
                    code:2,
                     name:"hi"
                }
              ]
}