title: What is parent Component for in JFolderChooser.showOpenDialog
body: <p>Case 1:</p>
  
  <pre><code>JFileChooser myFileChooser;
  myFileChooser.showOpenDialog(this); //this = parent Component
  </code></pre>
  
  <p>Case 2:</p>
  
  <pre><code>JFileChooser myFileChooser;
  myFileChooser.showOpenDialog(null);
  </code></pre>
  
  <p>What is the practical difference between the two cases?</p>