{"ast_node_type":"function","tokens":[{"end":86,"kind":"keyword","start":0,"text":"pub"}]}
    pub fn opt_item_name(self, def_id: impl IntoQueryParam<DefId>) -> Option<Symbol> {
    /// Look up the name of a definition across crates. This does not look at HIR.
        let def_id = def_id.into_query_param();