code: def testPhantomVertex(self):
      v = self.g.vs[9]
      v.delete()
  
      # v is now a phantom vertex; try to freak igraph out now :)
      self.assertRaises(ValueError, v.update_attributes, a=2)
      self.assertRaises(ValueError, v.__getitem__, "a")
      self.assertRaises(ValueError, v.__setitem__, "a", 4)
      self.assertRaises(ValueError, v.__delitem__, "a")
      self.assertRaises(ValueError, v.attributes)
  
imports: import unittest
  from igraph import Graph, Vertex, VertexSeq
  from .utils import is_pypy
label_desc: Use image node_id 5 for calling the VertexTests obj's underlying member method code with example usage: obj.testPhantomVertex() without return types