Function verify_unique_signature 

pub fn verify_unique_signature(
    std_lib: &ZkStdLib,
    layouter: &mut impl Layouter<JubjubBase>,
    dst_signature: &AssignedNative<JubjubBase>,
    generator: &AssignedNativePoint<Jubjub>,
    vk: &AssignedNativePoint<Jubjub>,
    s: &AssignedScalarOfNativeCurve<Jubjub>,
    c: &AssignedScalarOfNativeCurve<Jubjub>,
    c_native: &AssignedNative<JubjubBase>,
    hash: &AssignedNativePoint<Jubjub>,
    sigma: &AssignedNativePoint<Jubjub>,
) -> Result<(), Error>