old_contents: from __future__ import absolute_import, unicode_literals
  
  import logging
  
  import pykka
  
  logger = logging.getLogger(__name__)
  
  
  def send(cls, event, **kwargs):
      listeners = pykka.ActorRegistry.get_by_class(cls)
      logger.debug('Sending %s to %s: %s', event, cls.__name__, kwargs)
      for listener in listeners:
          # Save time by calling methods on Pykka actor without creating a
          # throwaway actor proxy.
          #
          # Because we use `.tell()` there is no return channel for any errors,
          # so Pykka logs them immediately. The alternative would be to use
          # `.ask()` and `.get()` the returned futures to block for the listeners
          # to react and return their exceptions to us. Since emitting events in
          # practise is making calls upwards in the stack, blocking here would
          # quickly deadlock.
          listener.tell({
              'command': 'pykka_call',
              'attr_path': ('on_event',),
              'args': (event,),
              'kwargs': kwargs,
          })
  
  
  class Listener(object):
  
      def on_event(self, event, **kwargs):
          """
          Called on all events.
  
          *MAY* be implemented by actor. By default, this method forwards the
          event to the specific event methods.
  
          :param event: the event name
          :type event: string
          :param kwargs: any other arguments to the specific event handlers
          """
          try:
              getattr(self, event)(**kwargs)
          except Exception:
              # Ensure we don't crash the actor due to "bad" events.
              logger.exception(
                  'Triggering event failed: %s(%s)', event, ', '.join(kwargs))
  
new_contents: from __future__ import absolute_import, unicode_literals
  
  import logging
  
  import pykka
  from pykka.messages import ProxyCall
  
  logger = logging.getLogger(__name__)
  
  
  def send(cls, event, **kwargs):
      listeners = pykka.ActorRegistry.get_by_class(cls)
      logger.debug('Sending %s to %s: %s', event, cls.__name__, kwargs)
      for listener in listeners:
          # Save time by calling methods on Pykka actor without creating a
          # throwaway actor proxy.
          #
          # Because we use `.tell()` there is no return channel for any errors,
          # so Pykka logs them immediately. The alternative would be to use
          # `.ask()` and `.get()` the returned futures to block for the listeners
          # to react and return their exceptions to us. Since emitting events in
          # practise is making calls upwards in the stack, blocking here would
          # quickly deadlock.
          listener.tell(ProxyCall(
              attr_path=['on_event'],
              args=[event],
              kwargs=kwargs,
          ))
  
  
  class Listener(object):
  
      def on_event(self, event, **kwargs):
          """
          Called on all events.
  
          *MAY* be implemented by actor. By default, this method forwards the
          event to the specific event methods.
  
          :param event: the event name
          :type event: string
          :param kwargs: any other arguments to the specific event handlers
          """
          try:
              getattr(self, event)(**kwargs)
          except Exception:
              # Ensure we don't crash the actor due to "bad" events.
              logger.exception(
                  'Triggering event failed: %s(%s)', event, ', '.join(kwargs))
  
subject: Use Pykka 2's public API for fire-and-forget proxy calls