section>
    <section class="desc markdown">
      <p>Returns a <a href="dart-async/Future-class.html">Future</a> that completes once all buffered data is accepted by the
underlying <a href="dart-async/StreamConsumer-class.html">StreamConsumer</a>.</p>
<p>This method must not be called while an <a href="dart-io/IOSink/addStream.html">addStream</a> is incomplete.</p>
<p>NOTE: This is not necessarily the same as the data being flushed by the
operating system.</p>
    </section>
    
    <section class="summar