public static boolean isOwnHtmlAttribute(XmlAttributeDescriptor descriptor) {
    // common html attributes are defined mostly in common.rnc, core-scripting.rnc, etc
    // while own tag attributes are defined in meta.rnc
    final PsiElement declaration = descriptor.getDeclaration();
    final PsiFile file = declaration != null ? declaration.getContainingFile() : null;
    final String name = file != null ? file.getName() : null;
    return "meta.rnc".equals(name) || "web-forms.rnc".equals(name)
           || "embed.rnc".equals(name) || "tables.rnc".equals(name)
           || "media.rnc".equals(name);
  }
public static boolean isOwnHtmlAttribute(XmlAttributeDescriptor descriptor)