def METHOD_NAME(self, cls):
    '''
    List all children of a particular class recursively.
    You can either provide a class object, a class name,
    or the name of the container storing the class.
    '''
    # subclassing this to remove duplicate objects such as SpikeTrain
    # objects in both Segment and Group
    # Only Block can have duplicate items right now, so implement
    # this here for performance reasons.
    return unique_objs(super().METHOD_NAME(cls))