# Module DGraphTreeLayout

    module DGraphTreeLayout: sig .. end

    type cluster = string

    module Make: functor (Tree : Graph.Graphviz.GraphWithDotAttrs) -> functor (TreeManipulation : sigval is_ghost_node : Tree.V.t -> boolend) -> sig .. end

    module MakeFromDotModel: functor (Tree : Sig.G  with type V.label = DGraphModel.DotG.V.t
    		and type E.label = unit) -> functor (TreeManipulation : sigval is_ghost_node : Tree.V.t -> boolend) -> sig .. end