code: def setUp(self):
      self.link = _create_ln()
      self.link.cleargrads()
  
      self.shape = (self.batchsize, self.size)
      self.x = numpy.random.uniform(-1, 1, self.shape).astype(
          self.dtype
      )
      self.gy = numpy.random.uniform(-1, 1, self.shape).astype(
          self.dtype
      )
  
      self.check_forward_optionss = {"atol": 1e-4, "rtol": 1e-3}
      self.check_backward_optionss = {"atol": 1e-4, "rtol": 1e-3}
      if self.dtype == numpy.float16:
          self.check_forward_optionss = {"atol": 1e-3, "rtol": 1e-2}
          self.check_backward_optionss = {"atol": 5e-1, "rtol": 1e-1}
  
imports: import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import gradient_check
  from chainer import links
  from chainer import testing
  from chainer.testing import attr
  from chainer.testing import condition
  from chainer.utils import type_check
label_desc: Use image node_id 1 for calling the LayerNormalizationTest obj's underlying member method code with example usage: obj.setUp() without return types