 
 class BookShop: Shop {
     
-    var commodities: [Commodity]?
+    var books: [Book]?
     
     override func genericTypes() -> [String : String] {
-        var result = ["commodities" : String(Commodity)]
+        var result = ["books" : String(Book)]
         for (k, v) in super.genericTypes() {
             result[k] = v
         }

    
}

class Commodity: SwiftJSONModel {
    
    var name: String?
    var price: Int = 0

    "shopId" : 200010000,
    "shopName" : "Wisdom Bookshop",
    "shopAddress" : "No 7, Fortune Rd.",
    "books" : [
        [
            "name" : "Data Mining",
            "price" : 825
