I'm trying to understand a crash report I've got from crashlytics which looks like this:

```
Crashed: com.apple.main-thread
0  App                            0x104076730 RaceViewController.tableView(_:cellForRowAt:) + 4369164080 (<compiler-generated>:4369164080)
1  App                            0x104076800 @objc RaceViewController.tableView(_:cellForRowAt:) + 4369164288 (<compiler-generated>:4369164288)
2  UIKitCore                      0x1b6039b24 -[UITableView _createPreparedCellForGlobalRow:withIndexPath:willDisplay:] + 736
3  UIKitCore                      0x1b6007870 -[UITableView _updateVisibleCellsNow:] + 2500
4  UIKitCore                      0x1b60245d8 -[UITableView layoutSubviews] + 160
5  UIKitCore                      0x1b62f785c -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 2144
6  QuartzCore                     0x1b888a724 -[CALayer layoutSublayers] + 284
7  QuartzCore                     0x1b889087c CA::Layer::layout_if_needed(CA::Transaction*) + 468
8  QuartzCore                     0x1b889b3c0 CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 140
9  QuartzCore                     0x1b87e3f1c CA::Context::commit_transaction(CA::Transaction*, double) + 296
10 QuartzCore                     0x1b880d8bc CA::Transaction::commit() + 676
11 UIKitCore                      0x1b5e6ca30 _afterCACommitHandler + 140
12 CoreFoundation                 0x1b1d1a06c __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 32
13 CoreFoundation                 0x1b1d14f60 __CFRunLoopDoObservers + 420
14 CoreFoundation                 0x1b1d153dc __CFRunLoopRun + 968
15 CoreFoundation                 0x1b1d14ce8 CFRunLoopRunSpecific + 424
16 GraphicsServices               0x1bbe5f38c GSEventRunModal + 160
17 UIKitCore                      0x1b5e43444 UIApplicationMain + 1932
18 App                            0x104066764 main + 13 (Race.swift:13)
19 libdyld.dylib                  0x1b1b9c8f0 start + 4

```

I can see points to two places, `RaceViewController.tableView(_:cellForRowAt:)` & `Race.swift:13`.

Lets look at those two places in the code:

```
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let day = self.days[indexPath.section]
    var totalIndex = 0
    var raceIndex = 0
    for selectedRace in racesByDay[day]! {
        if (totalIndex == indexPath.row) {
            let cell = tableView.dequeueReusableCell(withIdentifier: "raceCell")! as! RaceCell
            cell.delegate = self
            cell.populate(event: self.event!, selectableRace: self.racesByDay[day]![raceIndex])
            return cell
        }
        if selectedRace.opened {
            if (indexPath.row <= totalIndex + selectedRace.race.classes.count) {
                let cell = tableView.dequeueReusableCell(withIdentifier: "competitorClassCell")! as! CompetitorClassCell
                cell.delegate = self
                cell.populate(competitorClass: selectedRace.race.classes[indexPath.row - totalIndex - 1], selectableRace: selectedRace)
                return cell
            }
            totalIndex += selectedRace.race.classes.count
        } else {
            totalIndex += 1
        }            
        raceIndex += 1
    }

    return tableView.dequeueReusableCell(withIdentifier: "raceCell")!
}

```

and Race.swift:

```
import UIKit
import SwiftyJSON

class Race {
    var id: String <-- this is line 13
    var name: String
    var viewerUrl: String
    var trackingStartTime: Date
    var trackingEndTime: Date
    var expectedStartDate: String
    var raceStarttime: Date?
    var mapPublicationTime: Date?
    var initialized: Bool

    ...

}

```

How can I understand where the crash happened with this information? I'm not able to reproduce the crash.