{"ast_node_type":"other","tokens":[{"end":57,"kind":"keyword","start":0,"text":"(impl_m,"}]}
    (impl_m, impl_sig): (ty::AssocItem, ty::FnSig<'tcx>),
    (trait_m, trait_sig): (ty::AssocItem, ty::FnSig<'tcx>),
    impl_trait_ref: ty::TraitRef<'tcx>,