code: def testCoverIndex(self):
      self.assertTrue(self.cl[0] == [0, 1, 2, 3])
      self.assertTrue(self.cl[1] == [3, 4, 5, 6, 9])
      self.assertTrue(self.cl[2] == [])
      self.assertTrue(self.cl[3] == [8, 9])
  
imports: import math
  import random
  import unittest
  from igraph import Clustering, CohesiveBlocks, Cover, Graph, Histogram, InternalError, UniqueIdGenerator, VertexClustering, compare_communities, split_join_distance, set_random_number_generator
label_desc: Use image node_id 2 for calling the CoverTests obj's underlying member method code with example usage: obj.testCoverIndex() without return types