fn report_trait_method_mismatch<'tcx>(
infcx: &InferCtxt<'tcx>,
cause: ObligationCause<'tcx>,
terr: TypeError<'tcx>,
(trait_m, trait_sig): (AssocItem, FnSig<'tcx>),
(impl_m, impl_sig): (AssocItem, FnSig<'tcx>),
impl_trait_ref: TraitRef<'tcx>
) -> ErrorGuaranteed