Write CSV
        :param datasets: Datasets
        :param filename: File Name

def _write_csv(self, datasets, filename):
        """
        Write CSV
        :param datasets: Datasets
        :param filename: File Name
        """
        with open('/'.join([self.output, filename]), mode='w', encoding=self.encoding) as write_file:
            writer = csv.writer(write_file, delimiter=',')
            for i, row in enumerate(datasets):
                if i == 0:
                    # header
                    writer.writerow(list(row.keys()))
                writer.writerow(list(row.values()))