Bindings to Graphviz for graph visualisation. (http://projects.haskell.org/graphviz/)

#4Can't use rank=same RankSame to group clustered nodes

I'd like to group clustered nodes using the following dot data {rank=same 4474 4475}
4474 [
fillcolor="#afb170"
,label=<<TABLE><TR><TD>Node1</TD> <TD><FONT POINT-SIZE="8">Core</FONT></TD></TR></TABLE>>];
4475 [
fillcolor="#afb170"
,label=<<TABLE><TR><TD>Node2</TD> <TD><FONT POINT-SIZE="8">Core</FONT></TD></TR></TABLE>>];
20 }

I am using the monadic types to print out the nodes but I cannot print them at the same rank without post processing the file to add that {rank=same 4474 4475} line.

Can you point me in the right direction , or add a function int Types.Monadic to do that?

Thanks.