code: def bigtable_readers(self):
          
          result = set()
          for member in self._bindings.get(BIGTABLE_READER_ROLE, ()):
              result.add(member)
          return frozenset(result)
docs: Access to bigtable.reader role memebers
  
          For example:
  
          .. literalinclude:: snippets.py
              :start-after: [START bigtable_readers_policy]
              :end-before: [END bigtable_readers_policy]