syntax_data: {"ast_node_type":"other","tokens":[{"end":44,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // `gen` continues return `None`
context_before:             CoroutineKind::Coroutine(_) => span_bug!(body.span, "`Coroutine`s cannot be fused"),
context_after:             CoroutineKind::Desugared(CoroutineDesugaring::Gen, _) => {