docs: @Nullable
    private static String _getFieldName (@Nullable final String sContentDisposition)
    {
      String sFieldName = null;
      if (sContentDisposition != null && sContentDisposition.toLowerCase (Locale.US).startsWith (RequestHelper.FORM_DATA))
      {
        // Parameter parser can handle null input
        final ICommonsMap <String, String> aParams = new ParameterParser ().setLowerCaseNames (true)
                                                                           .parse (sContentDisposition, ';');
        sFieldName = aParams.get ("name");
        if (sFieldName != null)
          sFieldName = sFieldName.trim ();
      }
      return sFieldName;
    }