GenServer.handle_continue

You're seeing just the callback handle_continue, go back to GenServer module for more information.
Link to this callback

handle_continue(continue, state)

View Source (optional)

Specs

handle_continue(continue :: term(), state :: term()) ::
  {:noreply, new_state}
  | {:noreply, new_state, timeout() | :hibernate | {:continue, term()}}
  | {:stop, reason :: term(), new_state}
when new_state: term()

Invoked to handle continue instructions.

It is useful for performing work after initialization or for splitting the work in a callback in multiple steps, updating the process state along the way.

Return values are the same as handle_cast/2.

This callback is optional. If one is not implemented, the server will fail if a continue instruction is used.