code: @Restricted(NoExternalUse.class)
      public static void deleteContentsRecursive(@Nonnull Path path, @Nonnull PathRemover.PathChecker pathChecker) throws IOException {
          newPathRemover(pathChecker).forceRemoveDirectoryContents(path);
      }
docs: Deletes the given directory contents (but not the directory itself) recursively using a PathChecker.
  @param path a directory to delete
  @param pathChecker a security check to validate a path before deleting
  @throws IOException if the operation fails