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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 is_in(allowed_values # type: Set ):
 """ 'Values in' validation_function generator. Returns a validation_function to check that x is in the provided set of allowed values :param allowed_values: a set of allowed values :return: """

    def is_in_allowed_values(x):
        if x in allowed_values:
            return True
        else:
            # raise Failure('is_in: x in ' + str(allowed_values) + ' does not hold for x=' + str(x))
            raise NotInAllowedValues(wrong_value=x, allowed_values=allowed_values)

    is_in_allowed_values.__name__ = 'is_in_{}'.format(allowed_values)
    return is_in_allowed_values