[boost] [graph] leda_graph.hpp - Succ_Adj_Edge etc. undocumented in LEDA?

Are functions like Succ_Adj_Edge inofficial? I googled for them and can't find any occurence in the official LEDA documentation. The "official way" seem to be member functions of the GRAPH class ... Obviously, in that case a reference to the graph would have to be stored in the iterator as well, so I see the advantage of the current solution. But shouldn't we stick to official interfaces? I stumbled over this while looking how to add support for the EdgeListGraph concept in the LEDA graph adapter ...