def get_storage(obj):
    """Get or create the audit log storage for the given object

    :param obj: Content object
    :returns: PersistentList
    """
    annotation = IAnnotations(obj)
    if annotation.get(SNAPSHOT_STORAGE) is None:
        annotation[SNAPSHOT_STORAGE] = PersistentList()
    return annotation[SNAPSHOT_STORAGE]
Get or create the audit log storage for the given object

    :param obj: Content object
    :returns: PersistentList