@classmethod
def _changes_are_easy(cls, event, series_data, date_data):
    """Returns True if the changes we want to make to event are easy to
        perform.

        Hard changes include changes to how the recurrence behaves and in start
        and end dates.

        :param event: The event we want to update.
        :type event: :class:`Event`.
        :param dict series_data: The desired recurrence behavior.
        :param dict date_data: The desired date for the event.
        """
    for k, v in series_data.iteritems():
        if getattr(event.parent_series, k) != v:
            return False
    for k, v in date_data.iteritems():
        if getattr(event, k) != v:
            return False
    return True
