syntax_data: {"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"while"}]}
source_snippet:             while !data.is_descendant_of(expn_id, data.outer_expn(glob_ctxt)) {
context_before:             let mut marks = Vec::new();
context_after:                 marks.push(data.remove_mark(&mut glob_ctxt));