code: public static void removeFilesHierarchy(File baseDir) throws IOException
    {
      Params.notNull(baseDir, "Base directory");
      Params.isDirectory(baseDir, "Base directory");
      log.debug("Remove files hierarchy with base directory |%s|.", baseDir);
      removeDirectory(baseDir);
    }
docs: Remove ALL files and directories from a given base directory. This method remove ALL files and directory tree,
  child of given <code>baseDir</code> but directory itself is not removed. As a result <code>baseDir</code> becomes
  empty, that is, no children. If exception occur base directory state is not defined, that is, some files may be
  removed and other may still be there.
  
  @param baseDir base directory to clean-up.
  @throws IOException if remove operation fails.