syntax_data: {"ast_node_type":"other","tokens":[{"end":88,"kind":"keyword","start":0,"text":"..ExpnData::default(ExpnKind::Desugaring(reason),"}]}
source_snippet:             ..ExpnData::default(ExpnKind::Desugaring(reason), self, edition, None, None)
context_before:             allow_internal_unstable,
context_after:         };