AMQPHelpers.Adapter.consume

You're seeing just the callback consume, go back to AMQPHelpers.Adapter module for more information.
Link to this callback

consume(channel, queue, consumer, options)

Specs

consume(
  channel :: AMQP.Channel.t(),
  queue :: String.t(),
  consumer :: pid() | nil,
  options :: keyword()
) :: {:ok, String.t()} | AMQP.Basic.error()

Registers a queue consumer process.

See AMQP.Basic.consume/4.