code: def setUp(self):
      self.lowprec_dtype = chainer.get_dtype(self.dtype)
      self.highprec_dtype = chainer.get_dtype(
          self.dtype, map_mixed16=numpy.float32
      )
  
      self.size = 3
      with chainer.using_config("dtype", self.dtype):
          self.link = links.GroupNormalization(self.groups)
      self.shape = (1, self.size, 1)
  
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 TestDefaultInitializer obj's underlying member method code with example usage: obj.setUp() without return types