public static async Task <Channel> GetOrCreateChannelAsync(this GenesysHttpClient _http, GenesysAuthTokenInfo authToken)
 => await GetLastChanngelAsync(_http, authToken, GetChanngelQuery.OAuthClient)
 ?? await _http.CreateChannelAsync(authToken);
 public static async Task <Channel> GetLastChanngelAsync(this GenesysHttpClient _http, GenesysAuthTokenInfo authToken, GetChanngelQuery query)
 => (await _http.GetChannelsAsync(authToken, query))
 .Where(ch => ch.Expires.HasValue).OrderByDescending(ch => ch.Expires).FirstOrDefault();