code: def test_hessian_assign_step_exception(self):
      with self.assertRaises(ValueError):
          # Don't have step parameter
          algorithms.Hessian(
              layers.Input(2) > layers.Sigmoid(3) > layers.Sigmoid(1),
              step=0.01,
          )
  
file_path: neupy/tests/algorithms/gd/test_hessian.py
imports: from functools import partial
  import numpy
  import tensorflow
  from neupy import algorithms, layers
  from neupy.utils import tensorflow_session
  from neupy.algorithms.gd.hessian import find_hessian_and_gradient
  from helpers import compare_networks
  from helpers import simple_classification
  from base import BaseTestCase
label_desc: Use image node_id 3 for calling the HessianTestCase obj's underlying member method code with example usage: obj.test_hessian_assign_step_exception() without return types