Select {
    pattern: Project {
        inner: Extend {
            inner: LeftJoin {
                left: Union {
                    arms: [
                        Bgp {
                            patterns: [
                                TriplePattern {
                                    subject: Variable(
                                        ?a,
                                    ),
                                    predicate: NamedNode(
                                        <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>,
                                    ),
                                    object: NamedNode(
                                        <https://x/X>,
                                    ),
                                },
                            ],
                        },
                        Bgp {
                            patterns: [
                                TriplePattern {
                                    subject: Variable(
                                        ?a,
                                    ),
                                    predicate: NamedNode(
                                        <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>,
                                    ),
                                    object: NamedNode(
                                        <https://x/Y>,
                                    ),
                                },
                            ],
                        },
                    ],
                },
                right: Bgp {
                    patterns: [
                        TriplePattern {
                            subject: Variable(
                                ?a,
                            ),
                            predicate: NamedNode(
                                <https://x/p>,
                            ),
                            object: Variable(
                                ?b,
                            ),
                        },
                    ],
                },
                expression: None,
            },
            variable: ?k,
            expression: Literal(
                "x"^^<http://www.w3.org/2001/XMLSchema#string>,
            ),
        },
        variables: [
            ?k,
        ],
    },
    dataset: QueryDataset {
        default: [],
        named: [],
    },
    base_iri: None,
    version: None,
}