def test_list_2ndlist_1element():
l_list1 = create_list(['d', 'c', 'b', 'a'])
l_list2 = create_list([1])
ref_to_head = merge_list(l_list1, l_list2)
assert ref_to_head.value == 'a'
assert l_list1.__str__() == 'a, 1, b, c, d'
def test_list_2nd_empty():
l_list2 = LinkedList()
l_list1 = create_list(['d', 'c', 'b', 'a'])
ref_to_head = merge_list(l_list1, l_list2)
assert ref_to_head.value == "a"
assert l_list1.__str__() == 'a, b, c, d'
def test_lists_equal():
l_list1 = create_list(['d', 'c', 'b', 'a'])
l_list2 = create_list(['h', 'g', 'f', 'e'])
ref_to_head = merge_list(l_list1, l_list2)
assert ref_to_head.value == "a"
assert l_list1.__str__() == 'a, e, b, f, c, g, d, h'
def test_1slist_shorter():
l_list1 = create_list(['d', 'c', 'b', 'a'])
l_list2 = create_list(['h', 'g', 'f', 'e', 'z'])
ref_to_head = merge_list(l_list1, l_list2)
assert ref_to_head.value == "a"
assert l_list1.__str__() == 'a, z, b, e, c, f, d, g, h'
def test_1slist_longer():
l_list1 = create_list(['d', 'c', 'b', 'a', 'z'])
l_list2 = create_list(['h', 'g', 'f', 'e'])
ref_to_head = merge_list(l_list1, l_list2)
assert ref_to_head.value == "z"
assert l_list1.__str__() == 'z, e, a, f, b, g, c, h, d'