public async Task Insert(IEnumerable <ulong> guildIds) { var guilds = await _guildAppService.Get(); var existingGuilds = guilds.ToList(); var allNewGuildIds = guildIds.Where(guildId => existingGuilds.FirstOrDefault(x => x.Id == guildId) is null).ToList(); if (!allNewGuildIds.Any()) { return; } await _guildAppService.Insert(allNewGuildIds.Select(id => new Guild(id))); }