public static @Nullable PsiType getWritablePropertyType(@Nullable XmlAttributeValue xmlAttributeValue) {
    final PsiClass tagClass = getTagClass(xmlAttributeValue);
    if (tagClass != null) {
      final PsiElement declaration = getAttributeDeclaration(xmlAttributeValue);
      if (declaration != null) {
        return getWritablePropertyType(tagClass, declaration);
      }
    }
    return null;
  }
public static @Nullable PsiType getWritablePropertyType(@Nullable XmlAttributeValue xmlAttributeValue)