Expr::Field {
    attrs: [],
    base: Expr::Field {
        attrs: [],
        base: Expr::Path {
            attrs: [],
            qself: None,
            path: Path {
                leading_colon: None,
                segments: [
                    PathSegment {
                        ident: Ident {
                            ident: "a",
                            span: #0 bytes(95..96),
                        },
                        arguments: PathArguments::None,
                    },
                ],
            },
        },
        dot_token: Dot,
        member: Member::Unnamed(
            Index {
                index: 0,
                span: #5 bytes(0..102),
            },
        ),
    },
    dot_token: Dot,
    member: Member::Unnamed(
        Index {
            index: 1,
            span: #5 bytes(0..102),
        },
    ),
}
TokenStream [
    Ident {
        ident: "a",
        span: #0 bytes(95..96),
    },
    Punct {
        ch: '.',
        spacing: Alone,
        span: #0 bytes(96..97),
    },
    Literal {
        kind: Integer,
        symbol: "0",
        suffix: None,
        span: #5 bytes(0..102),
    },
    Punct {
        ch: '.',
        spacing: Alone,
        span: #0 bytes(97..100),
    },
    Literal {
        kind: Integer,
        symbol: "1",
        suffix: None,
        span: #5 bytes(0..102),
    },
]

Expr::Field {
    attrs: [],
    base: Expr::Field {
        attrs: [],
        base: Expr::Path {
            attrs: [],
            qself: None,
            path: Path {
                leading_colon: None,
                segments: [
                    PathSegment {
                        ident: Ident {
                            ident: "a",
                            span: #0 bytes(95..96),
                        },
                        arguments: PathArguments::None,
                    },
                ],
            },
        },
        dot_token: Dot,
        member: Member::Unnamed(
            Index {
                index: 0,
                span: #0 bytes(97..98),
            },
        ),
    },
    dot_token: Dot,
    member: Member::Unnamed(
        Index {
            index: 1,
            span: #0 bytes(99..100),
        },
    ),
}
TokenStream [
    Ident {
        ident: "a",
        span: #0 bytes(95..96),
    },
    Punct {
        ch: '.',
        spacing: Alone,
        span: #0 bytes(96..97),
    },
    Literal {
        kind: Integer,
        symbol: "0",
        suffix: None,
        span: #0 bytes(97..98),
    },
    Punct {
        ch: '.',
        spacing: Alone,
        span: #0 bytes(98..99),
    },
    Literal {
        kind: Integer,
        symbol: "1",
        suffix: None,
        span: #0 bytes(99..100),
    },
]