{"ast_node_type":"other","tokens":[{"end":46,"kind":"keyword","start":0,"text":"#[salsa::invoke_interned(proc_macro_span)]"}]}
    #[salsa::invoke_interned(proc_macro_span)]
    /// user wrote in the file that defines the proc-macro.
    fn proc_macro_span(&self, fun: AstId<ast::Fn>) -> Span;