Restkit post with core data entities and relationship -

i trying post contents of entity(articles) , relationship(authors) restkit object mapping.

articles <->> authors article can have many authors.

my current object mapping below,

    rkobjectmapping *authormapping = [rkobjectmapping requestmapping];     [authormapping addattributemappingsfromarray:@[@"name",@"email"]];      rkobjectmapping *articlemapping = [rkobjectmapping requestmapping];    [articlemapping addattributemappingsfromarray:@[@"title",@"body",@"date"]];     rkrelationshipmapping * rel =[rkrelationshipmapping relationshipmappingfromkeypath:@"author" tokeypath:@"author" withmapping:authormapping];    [articlemapping addpropertymapping:rel];      rkobjectmapping *mapping = [rkobjectmapping requestmapping];    [mapping addpropertymapping:[rkrelationshipmapping relationshipmappingfromkeypath:@"singlearticle" tokeypath:@"singlearticle" withmapping:articlemapping]]; 

for mapping expecting json output array of authors below,

  {     "singlearticle": {         "author": [             {                 "email": "dadsa@",                 "name": "rk"             },             {                 "email": "3ldll",                 "name": "rjk"             }         ],         "body": "body content",         "date": "2014-05-16t15:54:40z",         "title": "some title"     } } 

but generated json output turns out fields in author class separate object below,

{     "singlearticle": {         "author": [             {                 "email": "dadsa@"             },             {                 "name": "rk"             },             {                 "email": "3ldll"             },             {                 "name": "rjk"             }         ],         "body": "body content",         "date": "2014-05-16t15:54:40z",         "title": "some title"     } } 

i not sure how missing here messes json feed above. thoughts produce proper json array of author objects?