/// <summary>
/// Read remarks.
/// </summary>
/// <typeparam name="TSource"></typeparam>
/// <typeparam name="TResult"></typeparam>
/// <typeparam name="TThrottle"></typeparam>
/// <param name="enumerable"></param>
/// <param name="selectKey"></param>
/// <param name="initialBandwidth"></param>
/// <param name="tag"></param>
/// <returns></returns>
/// <remarks>
/// Throttling can only slow down iteration. Throttling cannot accelerate/force iteration. Therefore, unless the
/// calling method requests the tasks in the returned enumeration faster than the tasks' Results are awaited,
/// the iteration will be sequention and Throttle will have a negligable effect. More specifically,
/// be sure to call a method such as Prespool, Batch, Array, etc before calling Await on the throttled IEnumerableAsync<Task<TResult>>.
/// </remarks>
public static IEnumerableAsync <Task <TResult> > Throttle <TSource, TResult, TThrottle>(this IEnumerableAsync <TSource> enumerable,
Func <TSource, IManagePerformance <TThrottle>, Task <TResult> > selectKey,
int desiredRunCount = 1,
ILogger log = default(ILogger))
{
var logScope = log.CreateScope($"Throttle[{Guid.NewGuid()}]");
var throttler = new PerformanceManager <TThrottle>(desiredRunCount, logScope);
return(enumerable
.Batch()
.SelectMany(
items =>
{
return items
.Select(item => throttler.RunTask(() => selectKey(item, throttler)));
}));
}