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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 find_mice(self, direction, mechanism, purviews=False):
 """Return the |MIC| or |MIE| for a mechanism. Args: direction (Direction):
 :|CAUSE| or |EFFECT|. mechanism (tuple[int]):
 The mechanism to be tested for irreducibility. Keyword Args: purviews (tuple[int]):
 Optionally restrict the possible purviews to a subset of the subsystem. This may be useful for _e.g._ finding only concepts that are "about" a certain subset of nodes. Returns: MaximallyIrreducibleCauseOrEffect: The |MIC| or |MIE|. """

        purviews = self.potential_purviews(direction, mechanism, purviews)

        if not purviews:
            max_mip = _null_ria(direction, mechanism, ())
        else:
            max_mip = max(self.find_mip(direction, mechanism, purview)
                          for purview in purviews)

        if direction == Direction.CAUSE:
            return MaximallyIrreducibleCause(max_mip)
        elif direction == Direction.EFFECT:
            return MaximallyIrreducibleEffect(max_mip)
        return validate.direction(direction)