How do I merge call and caller graph in doxygen?

I have both CALL_GRAPH and CALLER_GRAPH set to YES, and doxygen happily generates both call and caller graph for me, however is there a command or t开发者_开发技巧rick to merge these two graphs to a single "flow" graph?

That is, instead of a->B and B->c how do I get a->B->c?