[GRASS-dev] information regarding structure dglGraph_s of directed graph library

Hello everybody,
I am trying to use graph generated by Vect_net_build_graph(), hold by Map_info::graph.
This element is of type dglGraph_s, having a typedef to type GRAPH.
I want to access this graph structure. I couldn’t understand this from syntax which is declared in lib/vector/dglib/graph.h .
Also do i always need to specify cost of arcs in database only?

regards
jay