title: send message to topic based on message key using kafka streams
body: <p>I want to be able to send all records in a Kafkastream to a different topic based on the key of the message key.
  Ex. A stream in Kafka contains name as key and record as value. I want to fan out these records to different topic based on the key of the record</p>
  
  <p>data : (jhon -> {jhonsRecord}),(sean -> {seansRecord}),(mary -> {marysRecord}),(jhon -> {jhonsRecord2}),
  expected </p>
  
  <ul>
  <li>topic1 :name: jhon ->(jhon -> {jhonsRecord}),(jhon -> {jhonsRecord2})</li>
  <li>topic2 :sean-> (sean -> {seansRecord})</li>
  <li>topic3 :mary -> (mary -> {marysRecord})</li>
  </ul>
  
  <p>Below is the way I am doing this right now, but since the list of names is hudge this is slow. Plus even if there are records a few names, I need to traverse the entire list  Please suggest a fix</p>
  
  <pre><code>    for( String name : names )
      {
          recordsByName.filterNot(( k, v ) -&gt; k.equalsIgnoreCase(name)).to(name);
      } 
  </code></pre>