module type S =sig..end
module Tree:Graph.Graphviz.GraphWithDotAttrs
module TreeManipulation:sig..end
typecluster =string
class tree_model :XDot.Make(Tree).graph_layout -> TreeManipulation.t ->[[Tree.V.t, Tree.E.t, cluster]]DGraphModel.abstract_model
val tree : unit -> TreeManipulation.t