title: Why Document is null even after loadContent(...)? - (WebView JavaFx)
body: <p>Here is the simple code of MainController class initialize(...) method:</p>
  
  <pre><code>WebEngine webEngine = webView.getEngine();
  webEngine.loadContent("&lt;h1&gt;hello&lt;/h1&gt;"); // Successfully loaded on form
  Document doc = webEngine.getDocument(); // null 
  </code></pre>
  
  <p>Why <em>doc</em> is <em>null</em> and how to fix it?</p>