code: def get_dead_hosting_devices_info(self):
          
          res = []
          for hd_id in self.hosting_devices_backlog:
              hd = self.hosting_devices_backlog[hd_id]['hd']
              if hd['hd_state'] == cc.HD_DEAD:
                  res.append(hd['id'])
          return res
docs: Get a list of hosting devices that have been marked dead
          :return: List of dead hosting device ids