AMQPHelpers.Adapter.fetch_application_channel

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

fetch_application_channel(name)

Specs

fetch_application_channel(name :: binary() | atom()) ::
  {:ok, AMQP.Channel.t()} | {:error, any()}

Provides an easy way to access an AMQP.Channel.t/0.

See AMQP.Application.get_channel/1.