docs: def sort_elements_by_child_values(obj_pyxb, child_name_list):
      """In-place sort simple or complex elements in a PyXB object by values they contain
      in child elements.
  
      Args:
        obj_pyxb: PyXB object
  
        child_name_list: list of str
          List of element names that are direct children of the PyXB object.
  
      """
      obj_pyxb.sort(key=lambda x: [get_auto(getattr(x, n)) for n in child_name_list])