[
    Function(
        Function {
            start: (
                1,
                7,
            ),
            end: (
                1,
                33,
            ),
            name: SimpleIdentifier {
                span: (
                    1,
                    16,
                ),
                value: "foo",
            },
            attributes: [],
            parameters: FunctionParameterList {
                start: (
                    1,
                    19,
                ),
                end: (
                    1,
                    32,
                ),
                members: [
                    FunctionParameter {
                        start: (
                            1,
                            20,
                        ),
                        end: (
                            1,
                            30,
                        ),
                        name: SimpleVariable {
                            span: (
                                1,
                                28,
                            ),
                            name: "b",
                        },
                        attributes: [],
                        type: Some(
                            Nullable(
                                String,
                            ),
                        ),
                        variadic: false,
                        default: None,
                        by_ref: false,
                    },
                ],
            },
            return_type: None,
            by_ref: false,
            body: [],
        },
    ),
]
