code: def gpu_dist(self):
      if self.is_variable:
          gpu_params = {
              k: cuda.to_gpu(v.data) for k, v in self.params.items()
          }
          gpu_params = {
              k: chainer.Variable(v) for k, v in gpu_params.items()
          }
      else:
          gpu_params = {
              k: cuda.to_gpu(v) for k, v in self.params.items()
          }
      gpu_params.update(self.options)
      return self.dist(**gpu_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 4 for calling the distribution_unittest obj's underlying member method code with example usage: obj.gpu_dist() and returns: self