syntax_data: {"ast_node_type":"other","tokens":[{"end":55,"kind":"keyword","start":0,"text":"tcx.instantiate_bound_regions_with_erased(sig),"}]}
source_snippet:         tcx.instantiate_bound_regions_with_erased(sig),
context_before:         &LayoutCx::new(tcx, typing_env),
context_after:         extra_args,