Java Programming Language

How can I make @Test units for this code:

public class MineField { int rows; int columns; int maximumMines; boolean[][] minefield = new boolean [10][10]; int [][] minedNeighbours = new int[10][10]; int alreadyMined = 0; MineField(int row, int col, int maxMine){ rows = row; columns = col; maximumMines = maxMine; for (int i=0; i<10; i++){ for (int j=0; j<10; j++){ minefield[i][j] = false; minedNeighbours[i][j] = 0; } } } public boolean mineTile(int row, int col){ if (alreadyMined < maximumMines){ if (!minefield[row][col]){ minefield[row][col] = true; alreadyMined++; for (int i=0; i