title: Modifying an QJsonArray within a QJsonObject?
body: <p>How to modify an array which is already inside a QJsonObject structure?</p>
  <pre><code>QJsonObject data = QJsonDocument::fromJson(QByteArrayLiteral(&quot;{\&quot;array\&quot;:[1,2,3]}&quot;)).object();
  
  // TODO: Something to append numbers to the 1,2,3 array?
  
  // This doesn't work: 
  data[&quot;array&quot;].toArray().append(4);
  
  qInfo() &lt;&lt; data; // QJsonObject({&quot;array&quot;:[1,2,3]}), without the 4th element
  </code></pre>
  <p>toArray() seems to create a copy instead of returning a reference</p>