Generate presentation summaries in a reverse chronological order.

     A filter class can be supplied to filter summaries or bound the fetching process.

def get_summaries(client, filter=None):
    """ Generate presentation summaries in a reverse chronological order.

     A filter class can be supplied to filter summaries or bound the fetching process.
    """
    try:
        index = 0
        while True:
            rb = _RightBarPage(client, index)

            summaries = rb.summaries()
            if filter is not None:
                summaries = filter.filter(summaries)

            for summary in summaries:
                    yield summary

            index += len(summaries)
    except StopIteration:
        pass