code: def testNumPyIndexing(self):
      n = self.g.vcount()
      for i in range(self.g.vcount()):
          arr = np.array([i])
          self.assertEqual(i, self.g.vs[arr[0]].index)
          arr = np.array([-i - 1])
          self.assertEqual(n - i - 1, self.g.vs[arr[0]].index)
  
      arr = np.array([n])
      self.assertRaises(IndexError, self.g.vs.__getitem__, arr[0])
  
      arr = np.array([-n - 1])
      self.assertRaises(IndexError, self.g.vs.__getitem__, arr[0])
  
      arr = np.array([1.5])
      self.assertRaises(TypeError, self.g.vs.__getitem__, arr[0])
  
      ind = [1, 3, 5, 8, 3, 2]
      arr = np.array(ind)
      self.assertEqual(
          ind, [vertex.index for vertex in self.g.vs[arr.tolist()]]
      )
      self.assertEqual(
          ind, [vertex.index for vertex in self.g.vs[list(arr)]]
      )
  
imports: import unittest
  from igraph import Graph, Vertex, VertexSeq
  from .utils import is_pypy
label_desc: Use image node_id 4 for calling the VertexSeqTests obj's underlying member method code with example usage: obj.testNumPyIndexing() without return types