'Flush all of the collections that were split by artifact.'

def _FinalizeSplitCollection(self, output_collection_map):

    total = 0
    for (artifact_name, collection) in output_collection_map.iteritems():
        l = len(collection)
        total += l
        self.Log('Wrote    results    from    Artifact    %s    to    %s.    Collection    size    %d.', artifact_name, collection.collection_id, l)
    self.Log('Total    collection    size:    %d', total)
