@Override
      public boolean isFileVisible(VirtualFile file, boolean showHiddenFiles) {
        boolean b = super.isFileVisible(file, showHiddenFiles);
        if (!file.isDirectory()) {
          b &= FileTypeRegistry.getInstance().isFileOfType(file, XmlFileType.INSTANCE);
        }
        return b;
      }
@Override
      public boolean isFileVisible(VirtualFile file, boolean showHiddenFiles)