code: def fill_tree_from_xml(tag, ar_tree, namespace):
      # type: (_Element, ArTree, str) -> None
      
      for child in tag:  # type: _Element
          name_elem = child.find('./' + namespace + 'SHORT-NAME')
          # long_name = child.find('./' + namespace + 'LONG-NAME')
          if name_elem is not None and child is not None:
              fill_tree_from_xml(child, ar_tree.append_child(name_elem.text, child), namespace)
          if name_elem is None and child is not None:
              fill_tree_from_xml(child, ar_tree, namespace)
docs: Parse the xml tree into ArTree objects.