PulsarEx.ConsumerCallback.handle_messages

You're seeing just the callback handle_messages, go back to PulsarEx.ConsumerCallback module for more information.
Link to this callback

handle_messages(list, state)

Specs

handle_messages(
  [
    %PulsarEx.Pulserl.Structures.ConsumerMessage{
      consumer: term(),
      event_time: term(),
      id: term(),
      ordering_key: term(),
      partition_key: term(),
      payload: term(),
      properties: term(),
      publish_time: term(),
      redelivery_count: term(),
      topic: term()
    }
  ],
  state()
) :: [
  {:ack | :nack,
   %PulsarEx.Pulserl.Structures.ConsumerMessage{
     consumer: term(),
     event_time: term(),
     id: term(),
     ordering_key: term(),
     partition_key: term(),
     payload: term(),
     properties: term(),
     publish_time: term(),
     redelivery_count: term(),
     topic: term()
   }}
]