@classmethod
def form_data_from_series(cls, series):
    """Translate an :class:`EventSeries` into a dictionary of recurrence
        form data.

        :param series: The series to translate.
        :type series: :class:`EventSeries`

        :returns: Form data.
        :rtype: dict
        """
    return {'frequency': series.frequency, 'every': series.every, 'ends': 
        'on' if series.ends_on else 'after', 'num_occurrences': series.
        num_occurrences, 'recurrence_end_date': series.recurrence_end_date,
        'recurrence_summary': series.recurrence_summary}
