def _is_hierachy_searchable(child_id: str) -> bool:
    """ If the suffix of a child_id is numeric, the whole hierarchy is searchable to the leaf nodes.
        If the suffix of a child_id is alphabetic, the whole hierarchy is not searchable. """
    pieces_of_child_id_list = child_id.split('.')
    suffix = pieces_of_child_id_list[len(pieces_of_child_id_list) - 1]
    return suffix.isnumeric()