def test_linking_nodes(self):
node1 = Node('A')
node2 = Node('B')
node3 = Node('C')
# Link nodes together
node1.next = node2
node2.next = node3
# Node links should be transitive
assert node1.next is node2 # One link
assert node1.next.next is node3 # Two links
def prepend(self, item):
"""Insert the given item at the head of this linked list.
Runtime = 0(1).
"""
new_node = Node(item)
if self.is_empty():
self.head = new_node
self.tail = new_node
else:
new_node.next = self.head
self.head = new_node
