class TotalProductSalesWithCustomForm(TotalProductSales):
    report_title = _("Total Product Sales with Custom Form")
    report_description = _("Demonstrates a custom Form (form_class) that adds a product-size filter "
                           "alongside the standard date range filters.")
    form_class = TotalSalesFilterForm
    columns = [
        "name",
        "size",
        ComputationField.create(Sum, "quantity", verbose_name="Total quantity sold", is_summable=False),
        ComputationField.create(Sum, "value", name="sum__value", verbose_name="Total Value sold $"),
    ]