def test_insert_after(self):
l = SingleLinkedList([1])
node = l.get_n_th_node(0)
l.insert_after(node, 2)
self._check_list(l, (1, 2))
l.insert_after(node, 3)
self._check_list(l, (1, 3, 2))
l.insert_after(l.get_n_th_node(2), 7)
self._check_list(l, (1, 3, 2, 7))
