@Override
  @NotNull
  public StructureViewTreeElement getRoot() {
    XmlFile myFile = getPsiFile();
    if (myFile.getLanguage() == DTDLanguage.INSTANCE) return new DtdFileTreeElement(myFile);
    return new XmlFileTreeElement(myFile);
  }
@Override
  @NotNull
  public StructureViewTreeElement getRoot()