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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 bigtable_users(self):
 """Access to bigtable.user role memebers For example: .. literalinclude:: snippets.py :start-after: [START bigtable_users_policy] :end-before: [END bigtable_users_policy] """

        result = set()
        for member in self._bindings.get(BIGTABLE_USER_ROLE, ()):
            result.add(member)
        return frozenset(result)