syntax_data: {"ast_node_type":"other","tokens":[{"end":47,"kind":"keyword","start":0,"text":"self_ty.instantiate_identity(),"}]}
source_snippet:                 self_ty.instantiate_identity(),
context_before:                 ty::TypingEnv::post_analysis(self.tcx, impl_def_id),
context_after:                 impl_trait_ref.map(|impl_trait_ref| impl_trait_ref.instantiate_identity()),