[
    Expression {
        expr: Infix {
            lhs: List {
                items: [
                    ListItem {
                        key: Some(
                            LiteralString {
                                value: "foo",
                            },
                        ),
                        value: Variable(
                            Variable {
                                start: (
                                    3,
                                    15,
                                ),
                                name: "a",
                                end: (
                                    3,
                                    17,
                                ),
                            },
                        ),
                    },
                ],
            },
            op: Assign,
            rhs: Variable(
                Variable {
                    start: (
                        3,
                        21,
                    ),
                    name: "foo",
                    end: (
                        3,
                        25,
                    ),
                },
            ),
        },
    },
]