pub fn get_basepair_probs_mix<T, U>(
    alignfold: &AlignfoldWrapped<T, U>,
    basepair_prob_mats: &SparseProbMats<T>,
    basepair_probs_alifold: &SparseProbMat<U>,
    disables_alifold: bool
) -> SparseProbMat<U>where
    T: HashIndex,
    U: HashIndex,