private void updateExtensionsCombo() {
    Object source = getSource();
    if (source instanceof LanguageFileType) {
      List<String> extensions = getAllExtensions((LanguageFileType)source);
      if (extensions.size() > 1) {
        ExtensionComparator comp = new ExtensionComparator(extensions.get(0));
        extensions.sort(comp);
        SortedComboBoxModel<String> model = new SortedComboBoxModel<>(comp);
        model.setAll(extensions);
        myExtensionComboBox.setModel(model);
        myExtensionComboBox.setVisible(true);
        myExtensionLabel.setVisible(true);
        VirtualFile file = myExternalDocument ? FileDocumentManager.getInstance().getFile(myEditor.getDocument()) : null;
        String fileExt = file == null ? "" : FileUtilRt.getExtension(file.getName()); //NON-NLS
        if (!fileExt.isEmpty() && extensions.contains(fileExt)) {
          myExtensionComboBox.setSelectedItem(fileExt);
          return;
        }
        myExtensionComboBox.setSelectedIndex(0);
        return;
      }
    }
    myExtensionComboBox.setVisible(false);
    myExtensionLabel.setVisible(false);
  }
private void updateExtensionsCombo()