syntax_data: {"ast_node_type":"other","tokens":[{"end":43,"kind":"keyword","start":0,"text":"(ty::Opaque,"}]}
source_snippet:             (ty::Opaque, DefKind::OpaqueTy)
context_before:             (kind, tcx.def_kind(alias_ty.def_id)),
context_after:                 | (ty::Projection | ty::Inherent, DefKind::AssocTy)