code: def subtest_constraints(self):
      for s in self.samples:
          self.assertEqual(len(s), self.k)
  
          all(0 <= x < self.n for x in s)
  
          # distinct
          t = np.unique(s)
          self.assertEqual(len(t), self.k)
  
file_path: chainerrl/tests/misc_tests/test_random.py
imports: import timeit
  import unittest
  from chainer import testing
  from chainer.testing import condition
  import numpy
  from scipy import stats
  from chainerrl.misc.random import sample_n_k
label_desc: Use image node_id 2 for calling the TestSampleNK obj's underlying member method code with example usage: obj.subtest_constraints() without return types