code: def testMaximalIndependentVertexSets(self):
      self.assertEqual(
          self.g2.maximal_independent_vertex_sets(),
          [
              (0, 3, 4, 5, 6),
              (0, 3, 5, 6, 9),
              (0, 4, 5, 6, 7, 8),
              (0, 5, 6, 7, 8, 9),
              (1, 2, 7, 8, 9),
              (1, 5, 6, 7, 8, 9),
              (2, 3, 4),
              (2, 3, 9),
              (2, 4, 7, 8),
          ],
      )
  
imports: import unittest
  from igraph import Graph
  from .utils import temporary_file
label_desc: Use image node_id 4 for calling the IndependentVertexSetTests obj's underlying member method code with example usage: obj.testMaximalIndependentVertexSets() without return types