relation maintenances to equipment

equipment.py

@@ -133,12 +133,18 @@ class OpticalEquipment(Workflow, ModelSQL, ModelView):
 
 
     def get_maintenances_of_equipment(self, records):
-        raise UserError(str(self))
         pool = Pool()
         MaintenancesEquipment = pool.get('optical_equipment.maintenance')
         maintenancesEquipment = set()
 
-        pass
+        maintenancesEquipment = MaintenancesEquipment.search(['equipment', '=', self.id])
+        maintenances = []
+
+        #raise UserError(str(maintenancesEquipment))
+        for key in maintenancesEquipment:
+            maintenances.append(key.id)
+
+        return maintenances
     
     @classmethod
     def default_state(cls):