{"ast_node_type":"function","tokens":[{"end":81,"kind":"keyword","start":0,"text":"pub"}]}
    pub fn closure_kind(&self, closure_ty: Ty<'tcx>) -> Option<ty::ClosureKind> {
    /// `ClosureKind` may not yet be known.
        let unresolved_kind_ty = match *closure_ty.kind() {