public PersonalNotificationService(IDiscordBotConfig config,
                                           ILiveEmbedService embedService)
        {
            Config       = config;
            EmbedService = embedService;

            users = ImmutableDictionary <ulong, IUser> .Empty;

            EmbedService.Subscribe(NotifyUsers);
        }
        public ChannelUpdaterService(IDiscordBotConfig config,
                                     ILiveEmbedService embedService)
        {
            Config       = config;
            EmbedService = embedService;

            messages            = ImmutableDictionary <int, IUserMessage> .Empty;
            nextMessageWaitTime = DateTime.Now;

            EmbedService.Subscribe(UpdateChannel);
        }