def test_add(self):
"""Test add method."""
ul = UnorderedList()
ul.add(1)
self.assertFalse(ul.is_empty())
self.assertTrue(isinstance(ul.head, Node))
self.assertEqual(ul.head.get_data(), 1)
def test_is_empty(self):
"""Test is_empty method."""
ul = UnorderedList()
self.assertTrue(ul.is_empty())
ul.head = Node(1)
self.assertFalse(ul.is_empty())
