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


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

    
}

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