'* Validate existence of submitted Delivery Note
* Case nos do not overlap
* Check if packed qty doesn\'t exceed actual qty of delivery note
It is necessary to validate case nos before checking quantity'

def validate(self):

    self.validate_delivery_note()
    self.validate_items_mandatory()
    self.validate_case_nos()
    self.validate_qty()
    from erpnext.utilities.transaction_base import validate_uom_is_integer
    validate_uom_is_integer(self, u'stock_uom', u'qty')
    validate_uom_is_integer(self, u'weight_uom', u'net_weight')
