{"ast_node_type":"other","tokens":[{"end":46,"kind":"keyword","start":0,"text":"//"}]}
                        // skip `&` or `&mut `
                            + BytePos(min(old_prefix.len(), mutbl_b.ref_prefix_str().len()) as _);
                        let hi = sp.lo() + BytePos(old_prefix.len() as _);