public async Task WriteAsync( Stream output, MetricsDataValueSource metricsData, CancellationToken cancellationToken = default(CancellationToken)) { if (output == null) { throw new ArgumentNullException(nameof(output)); } var prometheusMetricsSnapshot = metricsData.GetPrometheusMetricsSnapshot(_options.MetricNameFormatter); await AsciiFormatter.Write(output, prometheusMetricsSnapshot, _options.NewLineFormat); }