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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 _subj_dict_from_pyxb(self, access_pyxb):
 """Return a dict representation of ``access_pyxb``, which is an AccessPolicy PyXB object. This also remove any duplicate subjects and permissions in the PyXB object. """

        subj_dict = {}
        for allow_pyxb in access_pyxb.allow:
            perm_set = set()
            for perm_pyxb in allow_pyxb.permission:
                perm_set.add(perm_pyxb)
            for subj_pyxb in allow_pyxb.subject:
                subj_dict.setdefault(subj_pyxb.value(), set()).update(perm_set)
        return subj_dict