code: def _helper_runningmeanstd():
      comm = MPI.COMM_WORLD
      np.random.seed(0)
      for triple, axis in [
          (
              (
                  np.random.randn(3),
                  np.random.randn(4),
                  np.random.randn(5),
              ),
              0,
          ),
          (
              (
                  np.random.randn(3, 2),
                  np.random.randn(4, 2),
                  np.random.randn(5, 2),
              ),
              0,
          ),
          (
              (
                  np.random.randn(2, 3),
                  np.random.randn(2, 4),
                  np.random.randn(2, 4),
              ),
              1,
          ),
      ]:
          x = np.concatenate(triple, axis=axis)
          ms1 = [x.mean(axis=axis), x.std(axis=axis), x.shape[axis]]
  
          ms2 = mpi_moments(triple[comm.Get_rank()], axis=axis)
  
          for a1, a2 in zipsame(ms1, ms2):
              print(a1, a2)
              assert np.allclose(a1, a2)
              print("ok!")
  
imports: from mpi4py import MPI
  import numpy
  from baselines.common import zipsame
label_desc: Use image node_id 4 for calling a global function with example usage: _helper_runningmeanstd() without return types