code: def setUp(self):
      self.target = utils.ParametersLink.from_param_props(
          ((2, 3), (2, 0, 1), ())
      )
      self.norm = math.sqrt(
          sum(
              [
                  np.square(param.grad).sum()
                  for param in self.target.params()
              ]
          )
      )
  
file_path: chainer/tests/chainer_tests/optimizer_hooks_tests/test_gradient_clipping.py
imports: import math
  import unittest
  import numpy
  import chainer
  from chainer import optimizer_hooks
  from chainer import optimizers
  from chainer import testing
  import utils
label_desc: Use image node_id 1 for calling the TestGradientClipping obj's underlying member method code with example usage: obj.setUp() without return types