def test_next(self):
stack = Stack()
stack_node = stack.StackNode(1)
next_stack_node = stack.StackNode(2)
self.assertEqual(stack_node.get_next(), None)
stack_node.set_next(next_stack_node)
self.assertEqual(stack_node.get_next(), next_stack_node)
self.assertEqual(next_stack_node.get_next(), None)
def test_init(self):
stack = Stack()
stack_node = stack.StackNode(3)
self.assertEqual(stack_node._StackNode__content, 3)
def test_content(self):
stack = Stack()
stack_node = stack.StackNode(1)
self.assertEqual(stack_node.get_content(), 1)
