private MongoDB.Document CreateDocument(ProductSales productSales)
{
var document = new MongoDB.Document();
document.Add("product-id", productSales.ProductId);
document.Add("product-name", productSales.ProductName);
document.Add("vendor-name", productSales.VendorName);
document.Add("total-quantity-sold", productSales.TotalQuantitySold);
document.Add("total-incomes", productSales.TotalIncome);
return document;
}