@Nullable
  public static PsiElement getAttValueToken(@NotNull XmlAttribute attribute) {
    final XmlAttributeValue valueElement = attribute.getValueElement();
    if (valueElement != null) {
      final PsiElement firstChild = valueElement.getFirstChild();
      if (firstChild != null) {
        final PsiElement nextSibling = firstChild.getNextSibling();
        return nextSibling instanceof XmlToken && ((XmlToken)nextSibling).getTokenType() == XmlTokenType.XML_ATTRIBUTE_VALUE_TOKEN
               ? nextSibling
               : null;
      }
    }
    return null;
  }
@Nullable
  public static PsiElement getAttValueToken(@NotNull XmlAttribute attribute)