syntax_data: {"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":"sig.map_bound(|sig|"}]}
source_snippet:     sig.map_bound(|sig| (trait_ref, sig.output()))
context_before:     let trait_ref = ty::TraitRef::new(tcx, fn_trait_def_id, [self_ty, arguments_tuple]);
context_after: }