anchor.diff:      .receiverChannel("udp://239.1.1.1:12001"));
   ----
   
  +=== Heartbeats
  +
  +AeronPublisher sends heartbeats to the instance of AeronSubscriber it is connected to
  +every `Context.heartbeatIntervalMillis' milliseconds. When the subscriber doesn't receive
  +any heartbeat from the publisher during the heartbeat interval * 1.5 it considers the session
  +with the publisher disconnected.
  +
  +When the publisher can't publish a heartbeat to the subscriber `Context.maxHeartbeatPublicationFailures`
  +times in a row then it shuts itself down.
  +
  +=== Auto-cancel functionality
  +
  +Both AeronSubscriber and AeronPublisher support auto-cancel functionality.
  +
  +When AeronSubscriber is created with `Context.autoCancel` set to true
  +it terminates its upstream subscription when the last publisher disconnects.
  +
  +When AeronPublisher is created with `Context.autoCancel` set to true
  +it shuts itself down when its subscriber is terminated as it expects the
  +corresponding subscriber instance it's connecting to to operate in auto-cancel
  +mode as well.
  +
   === Handling errors
   
   Error handler can be specified via `Context.errorConsumer` and is set by default to an error consumer logging exceptions.
  
positive.code:     .senderChannel("udp://serverbox:12000")
      .receiverChannel("udp://239.1.1.1:12001"));
  ----
  
  === AeronPublisher as client
  
  
negative.code:     .senderChannel("udp://serverbox:12000"));
  ----
  
  ==== Multiple sessions support for unicast
  
  AeronSubscriber supports connections from several remote AeronPublishers launched
  with different `Context.receiverChannel`.
  Each AeronPublisher communicates with AeronSubscriber within its own session.
  The demand is tracked by the subscriber per session.
  A slow AeronPublisher connected to AeronSubscriber will eventually block a fast consuming one.
  For the M1 a unicast session between AeronSubscriber and AeronPublisher requires a thread which is about
  to change in a following release.
  
  ==== Multicast sending mode
  
  To configure AeronSubscriber in multicast mode set field 'Context.receiverChannel' to a multicast Aeron channel.
  