code: def forward(self, inputs, device):
      x, gamma, beta = inputs
      y = functions.group_normalization(
          x, self.groups, gamma, beta, eps=self.eps
      )
      return (y,)
  
file_path: chainer/tests/chainer_tests/functions_tests/normalization_tests/test_group_normalization.py
imports: import numpy
  import six
  from chainer import functions
  import chainer.functions.normalization.group_normalization
  from chainer import testing
label_desc: Use image node_id 3 for calling the TestGroupNormalization obj's underlying member method code with example usage: obj.forward(inputs, device) and returns: y