Adding a new callback to the MySupervisor so that it can handle exiting children process

my_supervisor_new_callback.ex

## OTP Callbacks
def handle_info({:EXIT, dead_pid, _reason}, state) do
  
  # Start new process based on dead_pid spec
  {new_pid, child_spec} = state
  |> Map.get(dead_pid)
  |> start_child()
  
  # Remove the dead_pid and insert the new_pid with its spec
  new_state = state
  |> Map.delete(dead_pid)
  |> Map.put(new_pid, child_spec)
  
  {:noreply, new_state}
end