def test_set():
skiplist = SkiplistList()
assert skiplist.add(0, 10) == True
assert skiplist.add(1, 20) == True
assert skiplist.add(2, 10) == True
assert skiplist.add(3, 40) == True
assert skiplist.add(1, 40) == True
assert skiplist.set(0, 11) == True
assert skiplist.get(0) == 11
assert skiplist.set(2, 22) == True
assert skiplist.get(2) == 22
assert skiplist.set(3, 44) == True
assert skiplist.get(3) == 44
assert skiplist.set(2, 25) == True
assert skiplist.get(2) == 25
def test_set(): ###
skiplist = SkiplistList()
assert skiplist.add(0, 10) == True
assert skiplist.add(1, 20) == True
assert skiplist.add(2, 10) == True
assert skiplist.add(3, 40) == True
assert skiplist.add(1, 40) == True
assert skiplist.set(0, 11) == True
assert skiplist.get(0) == 11
assert skiplist.set(2, 22) == True
assert skiplist.get(2) == 22
assert skiplist.set(3, 44) == True
assert skiplist.get(3) == 44
assert skiplist.set(2, 25) == True
assert skiplist.get(2) == 25
assert skiplist.dummy.back.data == 40