method load_graph_from_file ?(gviz_cmd = "dot") fname =
let tmp_png = tempfile () in
let rc = Sys.command (mk_gviz_cmd gviz_cmd png_flags fname tmp_png) in
method load_graph_from_file ?(gviz_cmd = "dot") fname =
let tmp_png = tempfile () in
let rc = Sys.command (mk_gviz_cmd gviz_cmd png_flags fname tmp_png) in