title: How to represent an empty InputStream
body: <p>I'm reducing a stream of <code>InputStreams</code> like so:</p>
  
  <pre><code>InputStream total = input.collect(
      Collectors.reducing(
          empty,
          Item::getInputStream, 
          (is1, is2) -&gt; new SequenceInputStream(is1, is2)));
  </code></pre>
  
  <p>For the identity <code>InputStream</code>, I'm using:</p>
  
  <pre><code>InputStream empty = new ByteArrayInputStream(new byte[0]);
  </code></pre>
  
  <p>This works, but is there a better way to represent an empty <code>InputStream</code>?</p>