private static ExtensionToContentTypeMapper Create() { if (ExtensionToContentTypeMapper.instance != null) { return(ExtensionToContentTypeMapper.instance); } ExtensionToContentTypeMapper extensionToContentTypeMapper = new ExtensionToContentTypeMapper(); extensionToContentTypeMapper.BuildContentTypesFromAD(); extensionToContentTypeMapper.BuildContentTypesFromRegistry(); return(extensionToContentTypeMapper); }