Index out of range when selecting reusable tableview cell - swift

Question

I have the following class to keep track of all of the cells selected in the tableview, the issue is I keep receiving the error Index out of Range on the line:
self!.myModels[indexPath.row].isSelected ? self?.selectRow(indexPath) : self?.unselectRow(indexPath)
What is causing this? The issue occurs as soon as the tableView loads.
Rest of the code:
class CheckableTableViewCell: UITableViewCell {
var handler: ((Bool)->())?
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
self.selectionStyle = .none
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
self.accessoryType = selected ? .checkmark : .none
handler?(selected)
}
}
class TableViewController: UITableViewController {
private var myModels: [MyModel] = [MyModel(isSelected: false),MyModel(isSelected: true),MyModel(isSelected: true),MyModel(isSelected: false) ]
var sections = [Section]()
var structure = [Portfolios]()
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! CheckableTableViewCell
cell.handler = {[weak self] selected in
self?.myModels[indexPath.row].isSelected = selected
}
let section = sections[indexPath.section]
let item = section.items[indexPath.row]
cell.textLabel?.textAlignment = .left
cell.selectionStyle = .none
let titleStr = "\(item.code)
cell.textLabel!.text = titleStr
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let selectedIndexPath = indexPath.row
myModels[selectedIndexPath].isSelected = true
self.tableView.reloadRows(at: [indexPath], with: .none)
}
Sections defines the following tableView struct:
struct Section {
let name : String
var items : [Portfolios]
}
struct Portfolios: Decodable {
let code: String
enum CodingKeys : String, CodingKey {
case code
}
}