Astarte.Device.wait_for_connection

You're seeing just the function wait_for_connection, go back to Astarte.Device module for more information.
Link to this function

wait_for_connection(pid)

Specs

wait_for_connection(pid :: pid()) :: :ok

Blocks until the device succesfully connects to the broker, then returns :ok.

Useful to ensure the device has established the initial connection before beginning to publish.