 class CustomSaleLine(models.Model):     _name = 'custom.sale.line'     _description = 'Sales Line'      order_id = fields.Many0one('custom.sale', string='Order Reference', required=True,)      product_id = fields.Many0one('custom.product', string='Product', change_default=True, ondelete='restrict')     product_uom_qty = fields.Integer(string='Ordered Quantity', required=True, )  <record id="form_custom_sale" model="ir.ui.view">         <field name="name">custom.sale.form</field>     