code: def with_seed(seed=None):
      """
      A decorator for nosetests test functions that manages rng seeds.
  
      Parameters
      ----------
  
      seed : the seed to pass to np.random and mx.random
  
  
      This tests decorator sets the np, mx and python random seeds identically
      prior to each test, then outputs those seeds if the test fails or
      if the test requires a fixed seed (as a reminder to make the test
      more robust against random data).
  
      @with_seed()
      def test_ok_with_random_data():
          ...
  
      @with_seed(1234)
      def test_not_ok_with_random_data():
          ...
  
      Use of the @with_seed() decorator for all tests creates
      tests isolation and reproducability of failures.  When a
      test fails, the decorator outputs the seed used.  The user
      can then set the environment variable MXNET_TEST_SEED to
      the value reported, then rerun the test with:
  
          nosetests --verbose -s <test_module_name.py>:<failing_test>
  
      To run a test repeatedly, set MXNET_TEST_COUNT=<NNN> in the environment.
      To see the seeds of even the passing tests, add '--logging-level=DEBUG' to nosetests.
      """
  
      def test_helper(orig_test):
          @make_decorator(orig_test)
          def test_new(*args, **kwargs):
              test_count = int(os.getenv("MXNET_TEST_COUNT", "1"))
              env_seed_str = os.getenv("MXNET_TEST_SEED")
              for i in range(test_count):
                  if seed is not None:
                      this_test_seed = seed
                      log_level = logging.INFO
                  elif env_seed_str is not None:
                      this_test_seed = int(env_seed_str)
                      log_level = logging.INFO
                  else:
                      this_test_seed = np.random.randint(
                          0, np.iinfo(np.int32).max
                      )
                      log_level = logging.DEBUG
                  post_test_state = np.random.get_state()
                  np.random.seed(this_test_seed)
                  mx.random.seed(this_test_seed)
                  random.seed(this_test_seed)
                  logger = default_logger()
                  # 'nosetests --logging-level=DEBUG' shows this msg even with an ensuing core dump.
                  test_count_msg = (
                      "{} of {}: ".format(i + 1, test_count)
                      if test_count > 1
                      else ""
                  )
                  test_msg = (
                      "{}Setting test np/mx/python random seeds, use MXNET_TEST_SEED={}"
                      " to reproduce."
                  ).format(test_count_msg, this_test_seed)
                  logger.log(log_level, test_msg)
                  try:
                      orig_test(*args, **kwargs)
                  except:
                      # With exceptions, repeat test_msg at INFO level to be sure it's seen.
                      if log_level < logging.INFO:
                          logger.info(test_msg)
                      raise
                  finally:
                      np.random.set_state(post_test_state)
  
          return test_new
  
      return test_helper
  
file_path: mxboard/tests/python/unittest/common.py
imports: import sys, os, logging
  import mxnet
  import numpy
  import random
  import shutil
  from contextlib import contextmanager
  from nose.tools import make_decorator
  import tempfile
label_desc: Use image node_id 4 for calling a global function with example usage: with_seed(seed) and returns: test_helper, test_new