syntax_data: {"ast_node_type":"other","tokens":[{"end":83,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                     // The signature should be `Iterator::next(_) -> Option<Yield>`
context_before:                 hir::CoroutineKind::Desugared(hir::CoroutineDesugaring::Gen, _) => {
context_after:                     let option_did = tcx.require_lang_item(LangItem::Option, DUMMY_SP);