src/vs/workbench/api/common/extHostExtensionService.ts/getRemoteAuthorityPrefix
function getRemoteAuthorityPrefix(remoteAuthority: string): string {
	const plusIndex = remoteAuthority.indexOf('+');
	if (plusIndex === -1) {
		return remoteAuthority;
	}
	return remoteAuthority.substring(0, plusIndex);
}