private static XmlFile getReference(@NotNull Module module) {
    final URL resource = JavaFxSchemaProvider.class.getResource("fx.xsd");
    final VirtualFile fileByURL = VfsUtil.findFileByURL(resource);
    if (fileByURL == null) {
      LOG.error("xsd not found");
      return null;
    }

    PsiFile psiFile = PsiManager.getInstance(module.getProject()).findFile(fileByURL);
    LOG.assertTrue(psiFile != null);
    return (XmlFile)psiFile.copy();
  }
private static XmlFile getReference(@NotNull Module module)