static async Task Main(string[] args)
{
string inputTopic = "input", outputTopic = "output";
int numberPartitions = 4;
await CreateTopics(inputTopic, outputTopic, numberPartitions);
var config = new StreamConfig <StringSerDes, StringSerDes>();
config.ApplicationId = "sample-streamiz-demo";
config.BootstrapServers = "localhost:9092";
config.AutoOffsetReset = AutoOffsetReset.Earliest;
config.StateDir = Path.Combine(".");
config.CommitIntervalMs = 5000;
config.Guarantee = ProcessingGuarantee.AT_LEAST_ONCE;
config.MetricsRecording = MetricsRecordingLevel.DEBUG;
config.UsePrometheusReporter(9090, true);
StreamBuilder builder = new StreamBuilder();
builder.Stream <string, string>(inputTopic)
.FlatMapValues((v) => v.Split(" ").AsEnumerable())
.GroupBy((k, v) => v)
.Count()
.ToStream()
.MapValues((v) => v.ToString())
.To(outputTopic);
Topology t = builder.Build();
KafkaStream stream = new KafkaStream(t, config);
Console.CancelKeyPress += (o, e) => stream.Dispose();
await stream.StartAsync();
}