pub(crate) fn new_rtt_estimator() -> RoundtripTimeEstimator {

    RoundtripTimeEstimator::new(&params::build_rtt_params())

}

pub(crate) fn new_cwnd() -> CongestionWindow {

    CongestionWindow::new(&params::build_cwnd_params())

}

    fn build_fixed_params() -> FixedWindowParams {

        FixedWindowParamsBuilder::default()

            .circ_window_start(1000)

            .circ_window_min(100)

            .circ_window_max(1000)

            .build()

            .expect("Unable to build fixed window params")

    }

    pub(crate) fn build_cc_vegas_params() -> CongestionControlParams {

        // Following values are the default from the proposal. They likely differ from what the

        // consensus uses today.

        let params = VegasParamsBuilder::default()

            .cell_in_queue_params((186, 248, 310, 186, 600).into())

            .ss_cwnd_max(5000)

            .cwnd_full_gap(4)

            .cwnd_full_min_pct(Percentage::new(25))

            .cwnd_full_per_cwnd(1)

            .build()

            .expect("Unable to build Vegas params");

        CongestionControlParamsBuilder::default()

            .rtt_params(build_rtt_params())

            .cwnd_params(build_cwnd_params())

            .alg(Algorithm::Vegas(params.clone()))

            .fallback_alg(Algorithm::FixedWindow(build_fixed_params()))

            .build()

            .expect("Unable to build CC params")

    }

    pub(crate) fn build_cc_fixed_params() -> CongestionControlParams {

        let params = build_fixed_params();

        CongestionControlParamsBuilder::default()

            .rtt_params(build_rtt_params())

            .cwnd_params(build_cwnd_params())

            .alg(Algorithm::FixedWindow(params.clone()))

            .fallback_alg(Algorithm::FixedWindow(params))

            .build()

            .expect("Unable to build CC params")

    }

    pub(crate) fn build_rtt_params() -> RoundTripEstimatorParams {

        RoundTripEstimatorParamsBuilder::default()

            .ewma_cwnd_pct(Percentage::new(50))

            .ewma_max(10)

            .ewma_ss_max(2)

            .rtt_reset_pct(Percentage::new(100))

            .build()

            .expect("Unable to build RTT parameters")

    }

    pub(crate) fn build_cwnd_params() -> CongestionWindowParams {

        // Values taken from the prop324.

        CongestionWindowParamsBuilder::default()

            .cwnd_init(124)

            .cwnd_inc_pct_ss(Percentage::new(100))

            .cwnd_inc(1)

            .cwnd_inc_rate(31)

            .cwnd_min(124)

            .cwnd_max(u32::MAX)

            .sendme_inc(31)

            .build()

            .expect("Unable to build congestion window parameters")

    }