code: def testMatchingRetrieval(self):
      m = [12, 10, 8, 13, -1, 14, 9, -1, 2, 6, 1, -1, 0, 3, 5]
      self.assertEqual(self.matching.matching, m)
      for i, mate in enumerate(m):
          if mate == -1:
              self.assertFalse(self.matching.is_matched(i))
              self.assertEqual(self.matching.match_of(i), None)
          else:
              self.assertTrue(self.matching.is_matched(i))
              self.assertEqual(self.matching.match_of(i), mate)
              self.assertEqual(
                  self.matching.match_of(leda_graph.vs[i]).index,
                  leda_graph.vs[mate].index,
              )
  
file_path: python-igraph/tests/test_matching.py
imports: import unittest
  from igraph import Graph, InternalError, Matching
label_desc: Use image node_id 3 for calling the MatchingTests obj's underlying member method code with example usage: obj.testMatchingRetrieval() without return types