partner = self.pool.get('res.partner').browse(cr, uid, partner_id)
taxes = self.pool.get('account.tax').browse(cr, uid,prod['supplier_taxes_id'])
res['value']['taxes_id'] = self.pool.get('account.fiscal.position').map_tax(cr, uid, partner, taxes)
+ # res['value']['taxes_id'] = [x.id for x in taxes]
res2 = self.pool.get('product.uom').read(cr, uid, [uom], ['category_id'])
res3 = self.pool.get('product.uom').read(cr, uid, [prod_uom_po], ['category_id'])