syntax_data: {"ast_node_type":"variable","tokens":[{"end":63,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let span = if coroutine_kind.is_fn_like() {
context_before:                     // not working, so just hack around it by grabbing the parent fn's span.
context_after:                         tcx.def_span(tcx.local_parent(def_id))