def test_ll2_empty(self, ll1, ll2):
ll1.append(1)
ll1.append(2)
ll1.append(3)
merged_list = LinkedList.mergeLists(ll1, ll2)
assert merged_list.val == 1
assert merged_list.next.val == 2
assert merged_list.next.next.val == 3
def test_ll2_longer(self, ll1, ll2):
ll1.append(1)
ll1.append(2)
ll2.append(3)
ll2.append(4)
ll2.append(5)
ll2.append(6)
merged_list = LinkedList.mergeLists(ll1, ll2)
assert merged_list.val == 1
assert merged_list.next.val == 3
assert merged_list.next.next.val == 2
assert merged_list.next.next.next.val == 4
assert merged_list.next.next.next.next.val == 5
assert merged_list.next.next.next.next.next.val == 6
def test_both_ll_empty(self, ll1, ll2):
assert LinkedList.mergeLists(ll1, ll2) == None
