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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_graphviz_dirtree(self, engine="automatic", **kwargs):
 """ Generate directory graph in the DOT language. The graph show the files and directories in the node workdir. Returns: graphviz.Digraph <https://graphviz.readthedocs.io/en/stable/api.html#digraph> """

        if engine == "automatic":
            engine = "fdp"

        return Dirviz(self.workdir).get_cluster_graph(engine=engine, **kwargs)