@Override
  public boolean isValid() {
    final PsiFile psiFile = getPsiFile();
    if (psiFile == null || !psiFile.isValid()) {
      return false;
    }
    if (psiFile instanceof XmlFile) {
      final XmlDocument document = ((XmlFile)psiFile).getDocument();
      return document != null && document.getRootTag() != null;
    }
    return true;
  }
@Override
  public boolean isValid()