syntax_data: {"ast_node_type":"other","tokens":[{"end":56,"kind":"keyword","start":0,"text":"hir::CoroutineDesugaring::Async,"}]}
source_snippet:                         hir::CoroutineDesugaring::Async,
context_before:                     hir::CoroutineKind::Desugared(
context_after:                         hir::CoroutineSource::Block,