code: def TEST():
      
      grd = Grid(4,4, [2,4])
      grd.new_tile()
      grd.new_tile()
      print(grd)
      print("There are ", grd.count_blank_positions(), " blanks in grid 1\n")
  
      grd2 = Grid(5,5, ['A','B'])
      grd2.new_tile(26)
      print(grd2)
      build_board_checkers()
  
      print("There are ", grd2.count_blank_positions(), " blanks in grid 2")
docs: tests for this module