export class Market {
   constructor(public name: string, public code: number) { }
}

export class MarketDetails {
   constructor(
   public market: Market,
   public country: string
   ) {}

   public static convertFromJSON(dbItem: any) {
     const {
       marketName,
       marketId,
       country
     } = dbItem;

     return new MarketDetails(
     // THIS LINE
     marketName + " " + marketId = Market;
     country,
     );
   }
}