def get_AllIndexed(self, classes=None, index_sort=True):
    """
    Get all indexed children sorted by their ``@index``.

    Arguments:
        classes (list): Type of children (sans ``Indexed``) to return. \
            Default: ``['RegionRef', 'OrderedGroup', 'UnorderedGroup']``
        index_sort (boolean): Whether to sort by ``@index``

    Returns:
        a list of :py:class:`RegionRefIndexedType`, \
            :py:class:`OrderedGroupIndexedType`, and \
            :py:class:`UnorderedGroupIndexedType`
    """
    if not classes:
        classes = ['RegionRef', 'OrderedGroup', 'UnorderedGroup']
    ret = []
    for class_ in classes:
        ret += getattr(self, 'get_{}Indexed'.format(class_))()
    if index_sort:
        return sorted(ret, key=lambda x: x.index)
    return ret