         msg = "Responder with id #{responderId} timed out on channel '#{channel}'"
         err = new Error msg
 
-        bus.publish
+        core.bus.publish
           channel: replyTo.channel
           topic: replyTo.topic.err
           data: err


    timers.setImmediate ->
      topic = "request.#{topicId}"
      bus.publish
        channel: channel
        topic: topic
        data: data


  # for sending interrupts
  signal: (channel, data) ->

# Expose 'bus' access for internal methods, wiretaps.
# Non-enumerable, non-configurable, non-assignable.
Object.defineProperty core, 'bus', {value: bus}


module.exports = core