def test_LinkedList_insert_before_multiple_arg_long_head():
ll = LinkedList()
ll.insert("oranges", "kiwi", "bananas", "coconut")
ll.insert_before("kiwi", "1", "2", "3")
actual = str(ll)
expected = "{coconut} -> {bananas} -> {3} -> {2} -> {1} -> {kiwi} -> {oranges} -> NULL"
assert actual == expected
def test_LinkedList_insert_before_present_value():
ll = LinkedList()
ll.insert("oranges", "bananas", "coconut")
ll.insert_before("oranges", "kiwi")
actual = str(ll)
expected = "{coconut} -> {bananas} -> {kiwi} -> {oranges} -> NULL"
assert actual == expected
def test_LinkedList_insert_before_multiple_arg_just_head():
ll = LinkedList()
ll.insert("oranges")
ll.insert_before("oranges", "1", "2", "3")
actual = str(ll)
expected = "{3} -> {2} -> {1} -> {oranges} -> NULL"
assert actual == expected
def test_LinkedList_insert_before_empty_link():
ll = LinkedList()
actual = ll.insert_before("apples", "oranges")
expected = "Exception"
assert actual == expected
