Acessing fields within rule - ANtlr4 -

i have rule have declaration returns

tablename     returns [string fieldstring, tableobj obj] 

tableobj custom class declare in same g4 file

class tableobj {     public string realname;     public string aliasname;     public list<string> fields;     public list<relation> relations;      public tableobj(){        fields = new arraylist<string>();        relations = new arraylist<relation>();     } } 

but when have try access field of obj using $obj.field generated code is:

_localctx.field

instead of

_localctx.obj.field

how do obtain second form instead of first?

if need or follows snippet of rule

tablename returns [string fieldstring, tableobj obj] :     (tableprefix=id {                          $obj.aliasname = $tableprefix.text;                         system.out.println( "alias = " + $tableprefix.text + " " + $obj.aliasname );                     } ; 

this bug in antlr should report project issue tracker: https://github.com/antlr/antlr4/issues