Function forward_hessian_nograd_sparse

pub fn forward_hessian_nograd_sparse<const N: usize, F>(
    f: &'_ dyn Fn(&[F; N]) -> Result<F, Error>,
) -> impl Fn(&[F; N], Vec<[usize; 2]>) -> Result<[[F; N]; N], Error> + '_
where
    F: Float + FromPrimitive + AddAssign,