Store.cs

class Store
{
  private double revenue;
  private List<string> storeProducts;
  
  public Store(RevenueGenerator generator)
  {
    revenue = generator.GenerateCurrentRevenue();
    storeProducts = new List<string>();
  }
  
  async Task UpdateStoreRevenue(Product product)
  {
    if(!storeProducts.Contains(product.Name))
    {
       var token = HelperClass.GenerateTokenOrSomething();
       await HelperClass.UpdateStoreRevenue(token, product);
       revenue += product.Price;
       storeProducts.Add(product.Name);
    }
  }
}