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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_constraint(self, twig=None, **kwargs):
 """ Filter in the 'constraint' context :parameter str constraint: name of the constraint (optional) :parameter **kwargs: any other tags to do the filter (except constraint or context) :return: :class:`phoebe.parameters.parameters.ParameterSet` """

        if twig is not None:
            kwargs['twig'] = twig
        kwargs['context'] = 'constraint'
        return self.get(**kwargs)