NServiceBus custom recoverability policy - Exponential backoff with jitter

ExponentialBackoffPolicy.cs

using System;
using NServiceBus;
using NServiceBus.Transport;

class ExponentialBackoffPolicy
{
    static Random random = new Random();

    public static RecoverabilityAction Process(RecoverabilityConfig config, ErrorContext context)
    {
        var action = DefaultRecoverabilityPolicy.Invoke(config, context);
        if (!(action is DelayedRetry)) return action;
        if (context.DelayedDeliveriesPerformed > config.Delayed.MaxNumberOfRetries) return action;
        double jitter;
        lock (random) jitter = random.NextDouble();
        jitter = 1 + jitter * 0.2;// max 20%
        var delayInSeconds = config.Delayed.TimeIncrease.TotalSeconds;
        var retries = context.DelayedDeliveriesPerformed;
        if (retries > 0) delayInSeconds *= Math.Pow(2, retries);
        delayInSeconds *= jitter;
        return RecoverabilityAction.DelayedRetry(TimeSpan.FromSeconds(delayInSeconds));
    }
}