code: def test_invalid_sections(self):
      x = numpy.zeros((2, 3, 4), dtype="f")
      with self.assertRaises(ValueError):
          functions.split_axis(x, [2, 1], 1)
  
imports: import unittest
  import numpy
  import six
  import chainer
  from chainer import functions
  from chainer import testing
  from chainer.testing import backend
label_desc: Use image node_id 3 for calling the TestSplitAxisInvalidSections obj's underlying member method code with example usage: obj.test_invalid_sections() without return types