-spec handle_call(term(), gen_server:from(), map()) -> {reply, term(), map()}.

-spec handle_cast(term(), map()) -> {noreply, map()}.

-spec handle_info(term(), map()) -> {noreply, map()}.

-spec init([]) -> {ok, map()}.

-spec start_link() -> gen_server:start_ret().

-spec terminate(term(), map()) -> ok.