code: def check_mean(self, is_gpu):
      if is_gpu:
          mean1 = self.gpu_dist.mean.data
      else:
          mean1 = self.cpu_dist.mean.data
  
      if self.scipy_onebyone:
          mean2 = []
          for one_params in self.scipy_onebyone_params_iter():
              mean2.append(self.scipy_dist.mean(**one_params))
          mean2 = numpy.vstack(mean2).reshape(
              self.shape + self.cpu_dist.event_shape
          )
      else:
          mean2 = self.scipy_dist.mean(**self.scipy_params)
      array.assert_allclose(mean1, mean2)
  
imports: import functools
  import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer.testing import array
  from chainer.testing import attr
  from chainer import utils
label_desc: Use image node_id 27 for calling the distribution_unittest obj's underlying member method code with example usage: obj.check_mean(is_gpu) without return types