code: def test_invalid_axis(self):
      with self.assertRaises(TypeError):
          functions.rollaxis(self.x, "a", start=0)
  
imports: import unittest
  import numpy
  from chainer.backends import cuda
  from chainer import functions
  from chainer import testing
  from chainer.testing import attr
  from chainer.utils import type_check
label_desc: Use image node_id 2 for calling the TestRollaxisInvalidTypeError obj's underlying member method code with example usage: obj.test_invalid_axis() without return types