Function cf_dist_utils::get_expected_shortfall_and_value_at_risk

pub fn get_expected_shortfall_and_value_at_risk<T>(
    alpha: f64, 
    num_u: usize, 
    x_min: f64, 
    x_max: f64, 
    fn_inv: T
) -> (f64, f64) where
    T: Fn(&Complex<f64>) -> Complex<f64> + Sync + Send,