I need an int main function setup that runs the program in Jgrasp using the below classes [Java]

package GUI; import java.awt.*; import java.awt.event.*; import javax.swing.*; // Defines a class Reversi public class Reversi{ // Defines main method public static void main(String args[]){ JFrame app = new JFrame("Reversi"); app.setContentPane(new GameBoard()); // handle window closing //---------------------- app.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE); app.addWindowListener ( new WindowAdapter(){ public void windowClosing(WindowEvent e){ System.exit(0); } } );// end addWindowListener app.pack(); //need this to set application size app.setVisible(true); // do this after setting look and feel } }// end class Reversi //========================================================================== // The JPanel that displays the Game Board // class GameBoard extends JPanel{ private final int boardSize = 8; // number of squares on a side private int squareSize; // square size in pixels private int displaySize; // game size in pixels private int board[][]; // game board contents private final int EMPTY = 0; // board value for an empty square private final int BLACK = -1; // board value for a black piece private final int WHITE = 1; // board value for a white piece private int turn; // turn == WHITE or BLACK Image whitePiece; // references to the images Image blackPiece; Image emptySquare; //------------------------------------------------------- // Constructor // GameBoard(){ // allocate the game board array //------------------------------ board = new int[boardSize][boardSize]; // set all board squares to empty //------------------------------- for(int row = 0; row < boardSize; row++) for(int col = 0; col < boardSize; col++) board[row][col] = EMPTY; // setup the initial position //--------------------------- board[3][3] = board[4][4] = WHITE; board[3][4] = board[4][3] = BLACK; turn = BLACK; // load the images //------------------------------------- Toolkit t = Toolkit.getDefaultToolkit(); MediaTracker mt = new MediaTracker(this); mt.addImage(whitePiece = t.getImage("whitePiece80.jpg"), 0); mt.addImage(blackPiece = t.getImage("blackPiece80.jpg"), 0); mt.addImage(emptySquare = t.getImage("emptySquare80.png"), 0); try{ mt.waitForAll(); } catch (InterruptedException e) {}; // calculate the game size //------------------------ squareSize = emptySquare.getWidth(null); displaySize = boardSize*squareSize; setPreferredSize(new Dimension(displaySize, displaySize)); // Handle mouse clicks. //----------------------------------- addMouseListener(new MouseListener(){ public void mousePressed(MouseEvent e){ int row = e.getY()/squareSize; // find what square the mouse was clicked on int col = e.getX()/squareSize; if(board[row][col] != EMPTY) return; // don't allow a piece to go on top of another //================================================ // Put code here to compute flip list // Return if flip list is empty (not a legal move) //================================================ board[row][col] = turn; // place a piece on the selected square paintImmediately(0, 0, displaySize, displaySize); // draw the board before flipping try{ Thread.sleep(500); } catch (InterruptedException ex) { ; } // wait a moment //================================================ // Put piece flipping method call here. // Code below draws some pieces to illustrate how // to do piece flipping. //================================================ for (int c = col + 1; c < 8 && board[row][c] == EMPTY; c++){ board[row][c] = -turn; turn = -turn; // flip turn paintImmediately(0, 0, displaySize, displaySize); try{ Thread.sleep(100); } catch (InterruptedException ex) { ; } } turn = -turn; // flip turn } // Provide null implementations for remaining // required interface methods. //------------------------------------------- public void mouseClicked(MouseEvent e){} public void mouseEntered(MouseEvent e){} public void mouseExited(MouseEvent e){} public void mouseReleased(MouseEvent e){} }); setSize(displaySize, displaySize); setVisible(true); }// end constructor //------------------------------------- // Draw one square of the GameBoard // private void drawSquare(Graphics g, int row, int col){ int x = col*squareSize; int y = row*squareSize; if(board[row][col] == WHITE) g.drawImage(whitePiece, x, y, null); else if(board[row][col] == BLACK) g.drawImage(blackPiece, x, y, null); else g.drawImage(emptySquare, x, y, null); } //------------------------------------- // Draw the GameBoard // public void paintComponent(Graphics g){ for(int row = 0; row < boardSize; row++) for(int col = 0; col < boardSize; col++) drawSquare(g, row, col); } } // end class GameBoard