SPDX-License-Identifier: GPL-3.0-or-later

Copyright 2014-2020 Tong Sun <suntong001@users.sourceforge.net>
Copyright 2019      Joao Eriberto Mota Filho <eriberto@debian.org>

The original license notice:

    This package is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    This package is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program. If not, see <https://www.gnu.org/licenses/>

    On Debian systems, the complete text of the GNU General
    Public License version 3 can be found in "/usr/share/common-licenses/GPL-3".