{
   "sets" : [
      {
         "quantity" : "all",
         "class" : "Country"
      },
      {
         "quantity" : "all",
         "class" : "Cd"
      },
      {
         "quantity" : "all",
         "class" : "Track"
      },
      {
         "quantity" : "all",
         "class" : "Artist"
      }
   ],
   "might_have" : {
      "fetch" : 0
   },
   "belongs_to" : {
      "fetch" : 0
   },
   "has_many" : {
      "fetch" : 0
   }
}