Function affine_window_combine_one_endo_base 

fn affine_window_combine_one_endo_base<P: SWCurveConfig>(
    endo_coeff: P::BaseField,
    g1: &[Affine<P>],
    g2: &[Affine<P>],
    chal: ScalarChallenge<P::ScalarField>,
) -> Vec<Affine<P>>

Uses a batch version of Algorithm 1 of https://eprint.iacr.org/2019/1021.pdf (on page 19) to compute g1 + g2.scale(chal.to_field(endo_coeff))