class MultilineLabelCell: UITableViewCell {
    let label = UILabel()

    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        commonInit()
    }
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        commonInit()
    }
    private func commonInit() {
        label.translatesAutoresizingMaskIntoConstraints = false
        contentView.addSubview(label)
        let g = contentView.layoutMarginsGuide
        NSLayoutConstraint.activate([
            label.topAnchor.constraint(equalTo: g.topAnchor),
            label.leadingAnchor.constraint(equalTo: g.leadingAnchor),
            label.trailingAnchor.constraint(equalTo: g.trailingAnchor),
            label.bottomAnchor.constraint(equalTo: g.bottomAnchor),
        ])
        label.numberOfLines = 0
        // so we can see the framing
        label.backgroundColor = .yellow
    }

}

class ReloadRowsTestVC: UIViewController, UITableViewDelegate, UITableViewDataSource {

    var myData: [String] = []
    var reloadCount: Int = 0

    let tableView = UITableView()

    override func viewDidLoad() {
        super.viewDidLoad()

        // some sample data
        for i in 1..<50 {
            let nLines = i % 4
            var s: String = "Row: \(i-1)\nLine 1"
            for n in 0..<nLines {
                s += "\nLine \(n+2)"
            }
            myData.append(s)
        }
        myData[4] += "\nReload Count: 0"

        var cfg = UIButton.Configuration.filled()
        cfg.title = "Reload row 4"

        let btn = UIButton(configuration: cfg, primaryAction: UIAction() { _ in
            self.reloadCount += 1
            self.myData[4] += "\nRow 4 - Reload Count: \(self.reloadCount)"
            print("Reload Count:", self.reloadCount)
            self.tableView.reloadRows(at: [IndexPath(row: 4, section: 0)], with: .none)
        })

        btn.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(btn)

        tableView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(tableView)

        let g = view.safeAreaLayoutGuide
        NSLayoutConstraint.activate([

            btn.topAnchor.constraint(equalTo: g.topAnchor, constant: 20.0),
            btn.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 40.0),
            btn.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -40.0),

            tableView.topAnchor.constraint(equalTo: btn.bottomAnchor, constant: 20.0),
            tableView.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
            tableView.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),
            tableView.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: -20.0),

        ])

        tableView.register(MultilineLabelCell.self, forCellReuseIdentifier: "c")
        tableView.dataSource = self
        tableView.delegate = self

    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return myData.count
    }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        print("cellForRowAt:", indexPath)
        let c = tableView.dequeueReusableCell(withIdentifier: "c", for: indexPath) as! MultilineLabelCell
        c.label.text = myData[indexPath.row]
        return c
    }

}