code: def cpu_dist(self):
      params = self.params
      params.update(self.options)
      return self.dist(**params)
  
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 3 for calling the distribution_unittest obj's underlying member method code with example usage: obj.cpu_dist() and returns: self