syntax_data: {"ast_node_type":"other","tokens":[{"end":37,"kind":"keyword","start":0,"text":"tcx.def_span(def_id),"}]}
source_snippet:                 tcx.def_span(def_id),
context_before:             span_bug!(
context_after:                 "`assumed_wf_types` not defined for {} `{def_id:?}`",