in powershell-agent/src/main/java/jetbrains/buildServer/powershell/agent/detect/registry/RegistryPowerShellDetector.java [124:128]
private static File asDirectoryOrNull(@Nullable String path) {
if (path == null) return null;
final File directory = FileUtil.getCanonicalFile(new File(path));
return directory.isDirectory() ? directory : null;
}