syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"|"}]}
source_snippet:             | CoroutineKind::Desugared(CoroutineDesugaring::Gen, _) => {
context_before:             CoroutineKind::Desugared(CoroutineDesugaring::AsyncGen, _)
context_after:                 transform.insert_none_ret_block(body)