third_party/web_platform_tests/WebIDL/valid/idl/exception-inheritance.widl

// from http://lists.w3.org/Archives/Public/public-script-coord/2010OctDec/0112.html
  exception DOMException {
    unsigned short code;
  };

  exception HierarchyRequestError : DOMException { };
  exception NoModificationAllowedError : DOMException { };