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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 contains(ref_value):
 """ 'Contains' validation_function generator. Returns a validation_function to check that `ref_value in x` :param ref_value: a value that must be present in x :return: """

    def contains_ref_value(x):
        if ref_value in x:
            return True
        else:
            raise DoesNotContainValue(wrong_value=x, ref_value=ref_value)

    contains_ref_value.__name__ = 'contains_{}'.format(ref_value)
    return contains_ref_value