code: def setUp(self):
      (self.x,) = self.generate_inputs()
      self.gy = numpy.random.uniform(-1, 1, self.shape).astype(
          self.dtype
      )
  
      if self.dtype in (numpy.float16, chainer.mixed16):
          self.check_forward_options = {"atol": 1e-2, "rtol": 1e-1}
          self.check_backward_options = {"atol": 5e-1, "rtol": 1e-1}
      else:
          self.check_forward_options = {"atol": 1e-4, "rtol": 1e-3}
          self.check_backward_options = {"atol": 1e-3, "rtol": 1e-2}
  
imports: import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import links
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 1 for calling the GroupNormalizationTest obj's underlying member method code with example usage: obj.setUp() without return types