syntax_data: {"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"\"`assumed_wf_types`"}]}
source_snippet:                 "`assumed_wf_types` not defined for {} `{def_id:?}`",
context_before:                 tcx.def_span(def_id),
context_after:                 kind.descr(def_id.to_def_id())