meta() :: map
payload() :: binary
state() :: term
handle_info(meta, state) :: {:noreply, state} | {:stop, reason :: term, state}
handle_ready(meta, state) :: {:noreply, state} | {:stop, reason :: term, state}
handle_request(payload, meta, state) :: {:noreply, state} | {:reply, response :: binary, state} | {:stop, reason :: term, state}
init(initial :: term) :: GenServer.on_start
terminate(reason :: term, state) :: any