{"ast_node_type":"function","tokens":[{"end":70,"kind":"keyword","start":0,"text":"fn"}]}
            fn walk_ref(&$lt $self, $vis: &mut $vis_ty) -> V::Result {
        impl<$($K: $Kb,)? $lt, $vis_ty: Visitor<$lt>> Walkable<$lt, $vis_ty> for $self_ty {
                $block