code: def setUp(self):
      self.xs = [
          numpy.random.uniform(-1, 1, self.shape).astype(self.dtype),
          numpy.random.uniform(-1, 1, self.shape).astype(self.dtype),
      ]
      self.g = numpy.random.uniform(-1, 1, self.y_shape).astype(
          self.dtype
      )
      self.ggs = [
          numpy.random.uniform(-1, 1, self.shape).astype(self.dtype),
          numpy.random.uniform(-1, 1, self.shape).astype(self.dtype),
      ]
  
imports: import unittest
  import numpy
  import chainer
  from chainer import backend
  from chainer.backends import cuda
  from chainer import functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
  import chainerx
label_desc: Use image node_id 1 for calling the TestStack obj's underlying member method code with example usage: obj.setUp() without return types