code: def is_superset(reference_set  # type: Set
                  ):
      
      def is_superset_of(x):
          missing = reference_set - x
          if len(missing) == 0:
              return True
          else:
              # raise Failure('is_superset: len(reference_set - x) == 0 does not hold for x=' + str(x)
              #               + ' and reference_set=' + str(reference_set) + '. x does not contain required '
              #                       'elements ' + str(missing))
              raise NotSuperset(wrong_value=x, reference_set=reference_set, missing=missing)
  
      is_superset_of.__name__ = 'is_superset_of_{}'.format(reference_set)
      return is_superset_of
docs: 'Is superset' validation_function generator.
      Returns a validation_function to check that x is a superset of reference_set
  
      :param reference_set: the reference set
      :return: