fn ft_comm<F: FieldWitness, Scale>(
plonk: &Plonk<F::Scalar>,
t_comm: &PolyComm<GroupAffine<F>>,
verification_key: &PlonkVerificationKeyEvals<F>,
scale: Scale,
w: &mut Witness<F>,
) -> GroupAffine<F>where
Scale: Fn(GroupAffine<F>, <F::Scalar as FieldWitness>::Shifting, &mut Witness<F>) -> GroupAffine<F>,