public void CaptureWhitePiece(int r1, int c1, int r2, int c2) 
    {  
        // Check Valid Capture
        assert(Math.abs(r2-r1)==2 && Math.abs(c2-c1)==2);
        
        // Obtain the capture direction
        MoveDir dir = r2<r1?(c2<c1?MoveDir.forwardRight:MoveDir.forwardLeft)
                :(c2<c1?MoveDir.backwardRight:MoveDir.backwardLeft);
        
        // Removing White Piece from the board
        switch(dir){
            case forwardLeft:
                this.cell[r1-1][c1+1] = CellEntry.empty;
                break;
            case forwardRight:
                this.cell[r1-1][c1-1] = CellEntry.empty;
                break;
            case backwardLeft:
                this.cell[r1+1][c1+1] = CellEntry.empty;
                break;
            case backwardRight:
                this.cell[r1+1][c1-1] = CellEntry.empty;
                break;
        }
        
        // Decreasing the count of white pieces
        this.whitePieces--;
        
        // Making move
        this.MakeMove(r1, c1, r2, c2);
        //return dir;
    }