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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 add_edge(self, source, target, interaction='-', directed=True, dataframe=True):
 """ Add a single edge from source to target. """

        new_edge = {
            'source': source,
            'target': target,
            'interaction': interaction,
            'directed': directed
        }
        return self.add_edges([new_edge], dataframe=dataframe)