syntax_data: {"ast_node_type":"variable","tokens":[{"end":46,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:     let ty::CoroutineClosure(_, parent_args) =
context_before:     let parent_def_id = tcx.local_parent(coroutine_def_id);
context_after:         *tcx.type_of(parent_def_id).instantiate_identity().kind()