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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 to_dotfile(self, filename):
 """ Write graph to `filename`. The generated file should be handed over to the `dot` tool from the http://www.graphviz.org/ package:: $ dot tree.dot -T png -o tree.png """

        with codecs.open(filename, "w", "utf-8") as file:
            for line in self:
                file.write("%s\n" % line)