Swift 4 main thread warning

[Deleted user]

Main thread warning in this code.

/// You can change insertion/deletion animations like this! Fade works well.
    /// So does Top/Bottom. Left/Right/Middle are a little weird, but hey, do your thing.
    public var insertionAnimation = UITableViewRowAnimation.automatic, deletionAnimation = UITableViewRowAnimation.automatic

    override fileprivate func processChanges(newState: SectionedValues<Section, Value>, diff: [SectionedDiffStep<Section, Value>]) {
        guard let tableView = self.tableView else { return }
        tableView.beginUpdates()
        self._sectionedValues = newState
        for result in diff {
            switch result {
            case let .delete(section, row, _): tableView.deleteRows(at: [IndexPath(row: row, section: section)], with: self.deletionAnimation)
            case let .insert(section, row, _): tableView.insertRows(at: [IndexPath(row: row, section: section)], with: self.insertionAnimation)
            case let .sectionDelete(section, _): tableView.deleteSections(IndexSet(integer: section), with: self.deletionAnimation)
            case let .sectionInsert(section, _): tableView.insertSections(IndexSet(integer: section), with: self.insertionAnimation)
            }
        }
        tableView.endUpdates()
    }
}

[Jack Flintermann]

Yes, changing the rows or sectionedValues property on a DiffCalculator must be done on the main thread.