JPanel não apresenta componentes

Assuntos Gerais
#1 
  Oi, galera...fazendo uns testes aqui com o Miglayout, a aplicação só apresenta a janela vazia.

  Peguei o código no site do Mig e fiz algumas alterações. Também gostaria de saber por que a aplicação não está reconhecendo
  os métodos nos trechos de código que pus comentado..

import java.util.ArrayList;
import javax.swing.*;

import net.miginfocom.swing.MigLayout;
import net.miginfocom.layout.AC;
import net.miginfocom.layout.CC;
import net.miginfocom.layout.LC;


public class FrontEnd extends JFrame{
	
	JTabbedPane tabbedPane = new JTabbedPane();
	JTable table;
	JScrollPane scroll;
	ArrayList registros;
	private long codCliente;
	JPanel panel;
	
	public FrontEnd(){
		
		super("CADASTRO DE CLIENTES");
		setContentPane(new JPanel());
		setResizable(true);
		setVisible(true);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		LC layC = new LC().fill().wrap();
		AC colC = new AC().align("right",0).fill(1,3).grow(100,1,3).align("right",2).gap("15",1);
		AC rowC = new AC().index(6).gap("15!").align("top").grow(100,8);
		
		panel = new JPanel(new MigLayout(layC,colC,rowC));
		/* JPanel panel = createTabPanel(new MigLayout(layC,colC,rowC);*/
		panel.add(new JLabel("Last Name:"));
		panel.add(new JTextField());
		panel.add(new JLabel("First Name:"));
		panel.add(new JTextField(), new CC().wrap());
		panel.add(new JLabel("Phone:"));
		panel.add(new JTextField());
		panel.add(new JLabel("Email:"));
		panel.add(new JTextField());
		panel.add(new JLabel("Address 1:"));
		panel.add(new JTextField(), new CC().spanX().growX());
		panel.add(new JLabel("Address 2:"));
		panel.add(new JTextField(), new CC().spanX().growX());
		panel.add(new JLabel("City:"));
		panel.add(new JTextField(),new CC().wrap());
		panel.add(new JLabel("State:"));
		panel.add(new JTextField());
		panel.add(new JLabel("Postal Code:"));
		panel.add(new JTextField(10), new CC().spanX(2).growX(0));
		panel.add(new JLabel("Country:"));
		panel.add(new JTextField(),new CC().wrap());
		
		panel.add(/*createButton("New"), new CC().spanX(5),split(5).tag("other")*/ new JButton("New"));
		panel.add(/*createButton("Delete"), new CC().tag("other")*/new JButton("Delete"));
		panel.add(/*createButton("Edit"), new CC().tag("other")*/new JButton("Edit"));
		panel.add(/*createButton("Save"), new CC().tag("other")*/new JButton("Save"));
		panel.add(/*createButton("Cancel"), new CC().tag("Cancel")*/new JButton("Cancel"));
		
		tabbedPane.addTab("Layout showdown improved",panel);
	}


	public static void main(String[] args) {
		new FrontEnd();
	}

}
#2

Você da setContentPane(new JPanel()) e adiciona o panel com os items no tabbedPanel, useo como ContentPane

#3

Foi executado na 22 (?) e na 60 seria tabbedPane.add(“Layout showdown improved”,panel);
Só isso ?

#4