/**
* creating a PO
*
* @param Supplier $supplier
* @param string $supplierRefNo
* @param string $supplierContact
* @param string $supplierContactNumber
* @param string $shippingCost
* @param string $handlingCost
* @param bool $isCredit
*
* @return PurchaseOrder
*/
public static function create(Supplier $supplier, $supplierRefNo = '', $supplierContact = '', $supplierContactNumber = '', $shippingCost = 0, $handlingCost = 0, $isCredit = false, PurchaseOrder $fromPO = null)
{
$entity = new PurchaseOrder();
return $entity->setSupplier($supplier)->setSupplierRefNo(trim($supplierRefNo))->setSupplierContact($supplierContact)->setSupplierContactNumber($supplierContactNumber)->setshippingCost($shippingCost)->sethandlingCost($handlingCost)->setIsCredit($isCredit)->setFromPO($fromPO)->save();
}