{"ast_node_type":"other","tokens":[{"end":88,"kind":"keyword","start":0,"text":"//"}]}
                // Basically, a metavariable can never be joined with whatever after it.
                // rustc uses them mostly for pretty printing. So we have to deviate a bit from what rustc does here.
                Fragment::Tokens(tt) => builder.extend_with_tt_alone(tt.strip_invisible()),