def METHOD_NAME(self, filename):
    try:
        with open(filename, 'w') as file:
            json.dump(self.data, file, sort_keys=False, indent=4, separators=(',', ': '))
            file.write('\n')
            print('Written to file {}'.format(filename))
    except FileNotFoundError as e:
        err_print('{}.'.format(e))
        return False
    return True