def test_set_get_is_empty(self):
w = World(1, 1)
assert_true(w.is_empty(WorldPoint(w, 0, 0)))
w.set(WorldPoint(w, 0, 0), 'a')
assert_equal(w.get(WorldPoint(w, 0, 0)), 'a')
assert_false(w.is_empty(WorldPoint(w, 0, 0)))
def test_get(self):
w = World(1, 1)
assert_equal(w.get(WorldPoint(w, 0, 0)), '.')