     // MARK: - Actions
 
     @IBAction func handleButtonAction(_ sender: FormatBarItem) {
-        formatter?.handleActionForIdentifier(sender.identifier!)
+        guard let identifier = sender.identifier else { return }
+
+        formatter?.handleActionForIdentifier(identifier)
     }
 
     @IBAction func handleToggleButtonAction(_ sender: FormatBarItem) {


    struct Constants {
        static let fixedSeparatorMidPointPaddingX = CGFloat(5)
        static let fixedStackViewInsets = UIEdgeInsets(top: 0, left: 15, bottom: 0, right: 10)
        static let scrollableStackViewInsets = UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 10)
        static let stackViewCompactSpacing = CGFloat(0)
        static let stackViewRegularSpacing = CGFloat(0)
        static let stackButtonWidth = CGFloat(44)

        if visible {
            scrollableStackView.addArrangedSubviews(overflowItems)
            scrollableStackView.addArrangedSubview(overflowToggleItem)

            configureConstraints(for: overflowItems, in: stackView)
        } else {
            overflowItems.forEach({ item in
                item.removeFromSuperview()
                item.removeConstraints(item.constraints)
            })

            stackView.addArrangedSubview(overflowToggleItem)
        }
    }

    private func setOverflowToggleItemVisible(_ visible: Bool) {
        overflowToggleItem.removeFromSuperview()

        if visible {
            stackView.addArrangedSubview(overflowToggleItem)
            configureConstraints(for: [overflowToggleItem], in: stackView)
        }
    }
}
