@Override
  public boolean canFindUsagesFor(@NotNull PsiElement element) {
    return element instanceof XmlElementDecl ||
           element instanceof XmlAttributeDecl ||
           element instanceof XmlEntityDecl ||
           element instanceof XmlTag ||
           element instanceof XmlAttributeValue ||
           element instanceof PsiFile ||
           element instanceof XmlComment;
  }
@Override
  public boolean canFindUsagesFor(@NotNull PsiElement element)