code: def check_log_survival(self, is_gpu):
      smp = self.sample_for_test()
      if is_gpu:
          log_survival1 = self.gpu_dist.log_survival_function(
              cuda.to_gpu(smp)
          ).data
      else:
          log_survival1 = self.cpu_dist.log_survival_function(smp).data
      log_survival2 = self.scipy_dist.logsf(smp, **self.scipy_params)
      array.assert_allclose(log_survival1, log_survival2)
  
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 24 for calling the distribution_unittest obj's underlying member method code with example usage: obj.check_log_survival(is_gpu) without return types