Broadway v0.2.0 Broadway.CallerAcknowledger View Source
A simple acknowledger that sends a message back to a caller.
It must be stored as:
acknowledger: {Broadway.CallerAcknowledger, {pid, ref}, term}
The second element is a tuple with the pid to receive the messages and a unique identifier (usually a reference). The third element, which is per message, is ignored.
It sends a message in the format:
{:ack, ref, successful_messages, failed_messages}