syntax_data: {"ast_node_type":"other","tokens":[{"end":43,"kind":"keyword","start":0,"text":"def_id.to_def_id(),"}]}
source_snippet:                         def_id.to_def_id(),
context_before:                     let sig = tcx.liberate_late_bound_regions(
context_after:                         args.coroutine_closure_sig(),