library metadata; class SupportedBrowser { static const CHROME = "Chrome";   static const FIREFOX = "Firefox";   static const IE = "Internet Explorer";   static const OPERA = "Opera";   static const SAFARI = "Safari";   String get browserName => throw new UnsupportedError("SupportedBrowser.browserName is unsupported on this platform.");   String get minimumVersion => throw new UnsupportedError("SupportedBrowser.minimumVersion is unsupported on this platform.");   const SupportedBrowser(String browserName, [String minimumVersion]); } class Experimental { const Experimental(); } class DomName { String get name => throw new UnsupportedError("DomName.name is unsupported on this platform.");   const DomName(String name); } class DocsEditable { const DocsEditable(); } class Unstable { const Unstable(); }