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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 filter(self, networks):
 """ Returns a new experimental setup restricted to species present in the given list of networks Parameters networks : :class:`caspo.core.logicalnetwork.LogicalNetworkList` List of logical networks Returns ------- caspo.core.setup.Setup The restricted experimental setup """

        cues = self.stimuli + self.inhibitors
        active_cues = set()
        active_readouts = set()
        for clause, var in networks.mappings:
            active_cues = active_cues.union((l for (l, s) in clause if l in cues))
            if var in self.readouts:
                active_readouts.add(var)

        return Setup(active_cues.intersection(self.stimuli), active_cues.intersection(self.inhibitors), active_readouts)