code: def is_escalable(self, notification, escalations, timeperiods):
          
          cls = self.__class__
  
          # We search since when we are in notification for escalations
          # that are based on time
          in_notif_time = time.time() - notification.creation_time
  
          # Check is an escalation match the current_notification_number
          for escalation_id in self.escalations:
              escalation = escalations[escalation_id]
              escalation_period = timeperiods[escalation.escalation_period]
              if escalation.is_eligible(notification.t_to_go, self.state, notification.notif_nb,
                                        in_notif_time, cls.interval_length, escalation_period):
                  return True
  
          return False
docs: Check if a notification can be escalated.
          Basically call is_eligible for each escalation
  
          :param notification: notification we would like to escalate
          :type notification: alignak.objects.notification.Notification
          :param escalations: Esclations objects, used to get escalation objects (period)
          :type escalations: alignak.objects.escalation.Escalations
          :param timeperiods: Timeperiods objects, used to get escalation period
          :type timeperiods: alignak.objects.timeperiod.Timeperiods
          :return: True if notification can be escalated, otherwise False
          :rtype: bool