Adds some comments

Author: mynkow

src/Elders.Cronus/Projections/Rebuilding/RebuildProjectionSequentially_Job.cs

@@ -98,17 +98,21 @@ protected override async Task<JobExecutionStatus> RunJobAsync(IClusterOperations
             {
                 OnAggregateStreamLoadedAsync = async stream =>
                 {
+                    // 1. It is important to check all EventHandlers if they are interested in specific events and do this FIRST.
                     List<AggregateEventRaw> rawEvents = [];
                     foreach (string eventTypeContract in projectionEventsContractIds)
                     {
-                        var interested = stream.Commits
+                        IEnumerable<AggregateEventRaw> interested = stream.Commits
                             .SelectMany(x => x.Events)
                             .Where(x => IsInterested(eventTypeContract, x.Data));
 
+                        // Do not try to optimize the GC using Enumerable.Concat because it does not solve the issue
                         rawEvents.AddRange(interested);
                     }
 
-                    foreach (var eventRaw in rawEvents.OrderBy(x => x.Revision).ThenBy(x => x.Position))
+                    // 2. Then the result is sorted!
+                    IEnumerable<AggregateEventRaw> rawEventsSorted = rawEvents.OrderBy(x => x.Revision).ThenBy(x => x.Position); // Do not try to optimize the sorting with SortedDictionary. It is not faster.
+                    foreach (AggregateEventRaw eventRaw in rawEventsSorted)
                     {
                         var @event = serializer.DeserializeFromBytes<IEvent>(eventRaw.Data).Unwrap();
                         if (@event is null)