DispatchGroup-BadWay-1.swift

 guard let jsonDct:[String:Any] = readJsonFile() , let arrCategoriesDct:[[String:Any]] = jsonDct["categories"] as? [[String:Any]]  else { return }
        let categories:[Category] = arrCategoriesDct.compactMap { dct -> Category? in
            return Category(dct: dct)
        }
        
        var completedCount:Int = 0
        categories.forEach { category in
            self.asyncTask(imageURL: category.thumbnailImage, completion: { image in
               completedCount += 1
                if completedCount == categories.count {
                    print("Finished All Tasks")
                }
            })
        }