     fileprivate(set) var picker: UIPickerView = UIPickerView()
 
     // MARK: - Object life cycle
-    
+
+    /// Initializes and returns a newly allocated `NumericPicker` object with the specified frame rectangle.
+    /// - parameter frame: The frame rectangle for the view, measured in points. The origin of the frame is relative to 
+    ///     the superview in which you plan to add it.
     override public init(frame: CGRect) {
         super.init(frame: frame)
         picker.delegate = self


// MARK: - UIPickerViewDelegate
extension NumericPicker: UIPickerViewDelegate {
    public func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        let unicodeScalers = componentsString.unicodeScalars
        let index = unicodeScalers.index(unicodeScalers.startIndex, offsetBy: component)

        addSubview(picker)
    }

    /// Initializes and returns a newly allocated `NumericPicker` object with a zero-sized frame rectangle.
    convenience public init() {
        self.init(frame: CGRect.zero)
    }
