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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 _plot_methods(self):
 """A dictionary with mappings from plot method to their summary"""

        ret = {}
        for attr in filter(lambda s: not s.startswith("_"), dir(self)):
            obj = getattr(self, attr)
            if isinstance(obj, PlotterInterface):
                ret[attr] = obj._summary
        return ret