def test_example(self):
     
     path = get_path_to_molecule(self.starting_path, 'HH', self.d)
     expect = ['e' ,'O', 'HH']
     self.assertEqual(expect, path)
 def test_base_case_2(self):
     path = get_path_to_molecule(self.starting_path, 'O', self.d)
     self.assertEqual(['e', 'O'], path)