private async Task UnsubscribeFromPush(IEnumerable <MusicEndpoint> endpoints) { var channelOpt = Push.GetChannelOpt(); if (channelOpt != null) { var uriOpt = channelOpt.ChannelUri; if (uriOpt != null) { foreach (var endpoint in endpoints) { await WithClient(endpoint, client => DisablePush(client, uriOpt)); } } } }