code: def notify(self, level, value, target=None, ntype=None, rule=None):
          
          # Did we see the event before?
          if target in self.state and level == self.state[target]:
              return False
  
          # Do we see the event first time?
          if target not in self.state and level == 'normal' \
                  and not self.reactor.options['send_initial']:
              return False
  
          self.state[target] = level
          return self.reactor.notify(level, self, value, target=target, ntype=ntype, rule=rule)
docs: Notify main reactor about event.