def create_type_variant(cls, type_name, type_converter):
        """
        Create type variants for types with a cardinality field.
        The new type converters are based on the type converter with
        cardinality=1.

        .. code-block:: python

            import parse

            @parse.with_pattern(r'\d+')
            def parse_number(text):
                return int(text)

            new_type = CardinalityFieldTypeBuilder.create_type_variant(
                                    "Number+", parse_number)
            new_type = CardinalityFieldTypeBuilder.create_type_variant(
                                    "Number+", dict(Number=parse_number))

        :param type_name:  Type name with cardinality field suffix.
        :param type_converter:  Type converter or type dictionary.
        :return: Type converter variant (function).
        :raises: ValueError, if type_name does not end with CardinalityField
        :raises: MissingTypeError, if type_converter is missing in type_dict
        """
        assert isinstance(type_name, six.string_types)
        if not CardinalityField.matches_type(type_name):
            message = "type_name='%s' has no CardinalityField" % type_name
            raise ValueError(message)

        primary_name, cardinality = CardinalityField.split_type(type_name)
        if isinstance(type_converter, dict):
            type_dict = type_converter
            type_converter = type_dict.get(primary_name, None)
            if not type_converter:
                raise MissingTypeError(primary_name)

        assert callable(type_converter)
        type_variant = TypeBuilder.with_cardinality(cardinality,
                                    type_converter, listsep=cls.listsep)
        type_variant.name = type_name
        return type_variant