def test_one(self):
     self.assertEqual(staircase_num_ways(1), 1)
 def test_five(self):
     self.assertEqual(staircase_num_ways(5), 13)
 def test_three(self):
     self.assertEqual(staircase_num_ways(3), 4)
 def test_four(self):
     self.assertEqual(staircase_num_ways(4), 7)
 def test_two(self):
     self.assertEqual(staircase_num_ways(2), 2)