/**
   * Create a folder. The folder may even be on external SD card for Kitkat.
   *
   * @param file The folder to be created.
   * @return True if creation was successful.
   */
  public static boolean mkdir(final File file, Context context) {
    if (file == null) return false;
    if (file.exists()) {
      // nothing to create.
      return file.isDirectory();
    }

    // Try the normal way
    if (file.mkdirs()) {
      return true;
    }

    // Try with Storage Access Framework.
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP
        && FileUtil.isOnExtSdCard(file, context)) {
      DocumentFile document = getDocumentFile(file, true, context);
      // getDocumentFile implicitly creates the directory.

      return document.exists();
    }

    // Try the Kitkat workaround.
    if (Build.VERSION.SDK_INT == Build.VERSION_CODES.KITKAT) {
      try {
        return MediaStoreHack.mkdir(context, file);
      } catch (IOException e) {
        return false;
      }
    }

    return false;
  }