StoreList.cs

class Store
{
   private List<string> storeProducts;
   public Store()
   {
     storeProducts = new List<string>();
   }
  
   async Task<string> GetOrAddProduct(Product product)
   {
     if(storeProducts.Contains(product.Name))
     {
       return product;
     }
    
     var token = HelperClass.GenerateTokenOrSomething();
     await HelperClass.UploadProductDetails(token, product);
     storeProducts.Add(product.Name);
    
     return product.Name;
   }
}