title: Sequence of packets 'waitForBytesWritten' of QIODevice
body: <p>Are these codes the same behaviour for the remote:</p>
  
  <p>a:</p>
  
  <pre><code> socket.write("aaaa");
   socket.waitForBytesWrite(3000);
   socket.write("b");
  </code></pre>
  
  <p>b:</p>
  
  <pre><code> socket.write("aaaa");
   socket.write("b");
  </code></pre>
  
  <p>I know the first code will get "aaaab" but..
  I don't know if the second codes would result in "aabaa" or something else.</p>