pub fn validate_backorder_request(
sku: Sku,
requested: Quantity,
available_now: Quantity,
backordered: Quantity,
) -> Result<BackorderRequest, ValidationError>pub fn validate_backorder_request(
sku: Sku,
requested: Quantity,
available_now: Quantity,
backordered: Quantity,
) -> Result<BackorderRequest, ValidationError>