docs: public static void recursivelyCopyDirectory(final File sourceDir, final File destDir,
        final StandardCopyOption copyOption)
        throws IOException {
      checkNotNull(sourceDir);
      checkNotNull(destDir);
      checkArgument(sourceDir.isDirectory(), "Source directory does not exist");
      java.nio.file.Files.createDirectories(destDir.toPath());
      walkFileTree(sourceDir.toPath(), new CopyFileVisitor(sourceDir.toPath(), destDir.toPath(),
          copyOption));
    }