private static extern void toggl_on_online_state( IntPtr context, TogglDisplayOnlineState cb);
private static extern void toggl_on_online_state( IntPtr context, TogglDisplayOnlineState cb);
private static extern void toggl_on_online_state( IntPtr context, TogglDisplayOnlineState cb);
private static extern void toggl_on_online_state( IntPtr context, TogglDisplayOnlineState cb);