Convert file to regular text file.
        :return: None
        :rtype: :py:obj:`None`

def _to_textfile(self, file_generator):
        """Convert file to regular text file.
        :return: None
        :rtype: :py:obj:`None`
        """
        to_path = file_generator.to_path \
            if file_generator.to_path.endswith(file_generator.file_extension[file_generator.to_format]) \
            else file_generator.to_path + file_generator.file_extension[file_generator.to_format]

        with open(to_path, mode="w") as outfile:
            for f in file_generator:
                outfile.write(f.writestr(file_generator.to_format))