How can I call a method in a base Frame Renderer from the iOS Custom renderer?

I have this code:

public partial class PhrasesFrameRenderer : Frame
{
    Random rand = new Random();
    private int answeredPhraseCount;
    private int correctAns;

    public PhrasesFrameRenderer()
    {
        InitializeComponent();
        App.PhrasesFrameRenderer = this;

        public void abc()
        {

            ....
        };

and the custom Renderer

[assembly: ExportRenderer(typeof(PhrasesFrameRenderer), typeof(PhrasesFrameCustomRenderer))]
namespace Japanese.iOS
{
    public class PhrasesFrameCustomRenderer : FrameRenderer
    {
        UISwipeGestureRecognizer leftSwipeGestureRecognizer;
        UISwipeGestureRecognizer rightSwipeGestureRecognizer;
        PhrasesFrameRenderer frame;
        bool rightSwipeEnabled = false;

Can someone explain to me how I can call the ABC function in the Phrases FrameRenderer from the custom Renderer code.