Destroying Clicks
game.highlight('air') # highlight('air') , pair with put_block
game.highlight("block") # pair with digger (delete_block)
materials['air'] = 0
game.highlight('block')
# callbacks, hole, 1 block
put_hole(p):
big_hole(p) # 2*2
clear_column(p) # remove a column(10 blocks)
# make holes
game.on_click(put_hole)