syntax_data: {"ast_node_type":"other","tokens":[{"end":91,"kind":"keyword","start":0,"text":"impl_trait_ref.map(|impl_trait_ref|"}]}
source_snippet:                 impl_trait_ref.map(|impl_trait_ref| impl_trait_ref.instantiate_identity()),
context_before:                 self_ty.instantiate_identity(),
context_after:             )