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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def download_from_file(self, file_buffer, **kwargs):
 """ Download torrent using a file. :param file_buffer: Single file() buffer or list of. :param save_path: Path to download the torrent. :param label: Label of the torrent(s). :return: Empty JSON data. """

        if isinstance(file_buffer, list):
            torrent_files = {}
            for i, f in enumerate(file_buffer):
                torrent_files.update({'torrents%s' % i: f})
        else:
            torrent_files = {'torrents': file_buffer}

        data = kwargs.copy()

        if data.get('save_path'):
            data.update({'savepath': data['save_path']})
        return self._post('command/upload', data=data, files=torrent_files)