def METHOD_NAME(self, *args, **options):
    """ Main handler for the command."""
    file_path = options.get('csv_file_path', None)
    file_from_database = options['file_from_database']
    if file_from_database:
        csv_file = self.get_file_from_database()
        self.change_enrollments(csv_file)
    elif file_path:
        if not path.isfile(file_path):
            raise CommandError("File not found.")
        with open(file_path, 'rb') as csv_file:
            self.change_enrollments(csv_file)
    else:
        CommandError('No file is provided. File is required')