-record(config, {
    refresh :: fun((binary()) -> {ok, voauth:refresh_response()} |
        {error, voauth:refresh_error()}),
    on_refresh :: gleam@option:option(fun((voauth:token()) -> {ok, nil} |
        {error, binary()})),
    call_timeout_ms :: integer(),
    init_timeout_ms :: integer(),
    refresh_at_percent :: integer(),
    min_refresh_delay_ms :: integer(),
    retry_backoff_ms :: list(integer())
}).