def add_node(self, value):
node = LinkedNode(value)
if self.__size == 0:
self.__dummy.next_node = node
self.__dummy.prev_node = node
node.next_node = self.__dummy
node.prev_node = self.__dummy
else:
node.next_node = self.__dummy.next_node
node.prev_node = self.__dummy
self.__dummy.next_node.prev_node = node
self.__dummy.next_node = node
self.__size += 1
def test_assignment(self):
node1 = LinkedNode(4)
node2 = LinkedNode("string")
#Checking default values
self.assertEqual(node1.prev_node, None)
self.assertEqual(node1.next_node, None)
#Checking Node Assignment
try:
node1.next_node = node2
exception = False
except ValueError:
exception = True
self.assertFalse(exception)
with self.assertRaises(ValueError):
node2.next_node = "Bad Value"