How to use CombinableMatcher class of org.hamcrest.core package

import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Random;

import javax.swing.*;

public class MainFrame {

   public static void main(String[] args) {
      JFrame frame = new JFrame("8 Puzzle");
      frame.setVisible(true);
      frame.setSize(600, 600);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

      PieceManager pm = new PieceManager();
      frame.add(pm);

   }
}

class PieceManager extends JPanel {

   int[] possmoves;
   GameTile[] pieces;
   int openSpot;

   public PieceManager() {
      this.setSize(600, 600);
      this.setBackground(new Color(255, 255, 255));
      this.setLayout(new GridLayout(3, 3));
      pieces = new GameTile[9];
      this.init();
      this.addMouseListener(new ClickAction());
   }

   public void init() {
      ArrayList<Integer> nums = new ArrayList<Integer>();
      Random rand = new Random();
      for (int i = 0; i < 9; i++) {
         nums.add(i);
      }
      for (int i = 0, j = 8; i < 8; i++, j--) {
         int p = rand.nextInt(j);
         GameTile x = new GameTile(i, nums.remove(p));
         pieces[i] = x;
         nums.removeAll(Collections.singleton(null));
      }
      GameTile z = new GameTile(8, nums.get(0));
      pieces[8] = z;
      possmoves = new int[4];
      boolean found = false;
      for (int i = 0; i < 9 || found; i++) {
         if (pieces[i].getID() == 0) {
            openSpot = pieces[i].getPos();
         }
      }
      setOpenSpot();
      paint();
   }

   public void paint() {
      this.removeAll();
      for (int i = 0; i < 9; i++) {
         this.add(pieces[i]);
         pieces[i].setVisible(true);
      }
      revalidate(); // !!
      repaint(); // !!
   }

   public void setOpenSpot() {
      Arrays.fill(possmoves, -1);
      if (openSpot == 0) {
         possmoves[0] = 1;
         possmoves[1] = 3;
      } else if (openSpot == 1) {
         possmoves[0] = 0;
         possmoves[1] = 2;
         possmoves[3] = 4;
      } else if (openSpot == 2) {
         possmoves[0] = 1;
         possmoves[1] = 5;
      } else if (openSpot == 3) {
         possmoves[0] = 0;
         possmoves[1] = 4;
         possmoves[2] = 6;
      } else if (openSpot == 4) {
         possmoves[0] = 1;
         possmoves[1] = 3;
         possmoves[2] = 5;
         possmoves[3] = 7;
      } else if (openSpot == 5) {
         possmoves[0] = 2;
         possmoves[1] = 4;
         possmoves[3] = 8;
      } else if (openSpot == 6) {
         possmoves[0] = 3;
         possmoves[1] = 7;
      } else if (openSpot == 7) {
         possmoves[0] = 6;
         possmoves[1] = 4;
         possmoves[2] = 8;
      } else if (openSpot == 8) {
         possmoves[0] = 5;
         possmoves[1] = 7;
      }

   }

   public void checkCorrect() {

   }

   public class ClickAction implements MouseListener {

      @Override
      public void mouseClicked(MouseEvent e) {

         int x = e.getX();
         int y = e.getY();
         int pX = (int) Math.floor(x / 200);
         int pY = (int) Math.floor(y / 200);
         int piecepressed = (pY * 3) + pX;
         boolean moveable = false;
         int toBeMoved = -1;
         for (int i = 0; i < 4; i++) {
            if (piecepressed == possmoves[i]) {
               moveable = true;
               toBeMoved = possmoves[i];
            }
         }
         if (moveable) {
            GameTile saved = pieces[openSpot];
            pieces[openSpot] = pieces[toBeMoved];
            pieces[toBeMoved] = saved;
            openSpot = toBeMoved;
            setOpenSpot();
            paint();
            checkCorrect();
         }
      }

      @Override
      public void mouseEntered(MouseEvent arg0) {

      }

      @Override
      public void mouseExited(MouseEvent arg0) {

      }

      @Override
      public void mousePressed(MouseEvent arg0) {

      }

      @Override
      public void mouseReleased(MouseEvent arg0) {

      }
   }
}

class GameTile extends JComponent {

   private int id;
   private int position;

   public GameTile(int id, int initpos) {
      setBorder(BorderFactory.createTitledBorder("" + id)); // !!
      setLayout(new BorderLayout()); // !! so the added JLabel will show
      if (id == 0) {
         this.id = id;
         this.position = initpos;
      } else {
         this.id = id;
         this.position = initpos;
         String label = Integer.toString(id);
         // !! setSize(200, 200);
         setOpaque(true); // !!
         setPreferredSize(new Dimension(200, 200)); // !!
         setBackground(new Color(0, 0, 0));
         // !! Label l = new Label(label, Label.CENTER);
         JLabel l = new JLabel(label, SwingConstants.CENTER); // !!
         this.add(l);
         l.setVisible(true);
      }
   }

   public void setPos(int position) {
      this.position = position;
   }

   public int getPos() {
      return position;
   }

   public int getID() {
      return id;
   }
}

if (getIntent().getExtras() != null) {
    for (String key : getIntent().getExtras().keySet()) {
        String value = getIntent().getExtras().getString(key);
        Log.d(TAG, "Key: " + key + " Value: " + value);
    }
}

    <service android:name=".MyFirebaseMessagingService">
        <intent-filter>
            <action android:name="com.google.firebase.MESSAGING_EVENT" />
        </intent-filter>
    </service>
    <service android:name=".MyFirebaseInstanceIDService">
        <intent-filter>
            <action android:name="com.google.firebase.INSTANCE_ID_EVENT" />
        </intent-filter>
    </service>