syntax_data: {"ast_node_type":"other","tokens":[{"end":96,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // or `Poll::Ready(x)` and `Poll::Pending` respectively depending on the coroutine kind.
context_before:         // either `CoroutineState::Complete(x)` and `CoroutineState::Yielded(y)`,
context_after:         let mut transform = TransformVisitor {