syntax_data: {"ast_node_type":"other","tokens":[{"end":48,"kind":"keyword","start":0,"text":"ty::CoroutineWitness(did,"}]}
source_snippet:             ty::CoroutineWitness(did, args) => {
context_before:             ty::Coroutine(did, args) => ty::Coroutine(did, args.try_fold_with(folder)?),
context_after:                 ty::CoroutineWitness(did, args.try_fold_with(folder)?)