code: def unacknowledge_problem(self):
          
          if self.problem_has_been_acknowledged:
              logger.debug("[item::%s] deleting acknowledge of %s",
                           self.get_name(),
                           self.get_full_name())
              self.problem_has_been_acknowledged = False
              if self.my_type == 'host':
                  self.broks.append(self.acknowledgement.get_expire_brok(self.get_name()))
              else:
                  self.broks.append(self.acknowledgement.get_expire_brok(self.host_name,
                                                                         self.get_name()))
  
              # delete the comment of the item related with the acknowledge
              if hasattr(self.acknowledgement, 'comment_id') and \
                      self.acknowledgement.comment_id in self.comments:
                  del self.comments[self.acknowledgement.comment_id]
  
              # Should not be deleted, a None is Good
              self.acknowledgement = None
              self.broks.append(self.get_update_status_brok())
              self.raise_unacknowledge_log_entry()
docs: Remove the acknowledge, reset the flag. The comment is deleted
  
          :return: None