code: def mpi_rank_or_zero():
      """
      Return the MPI rank if mpi is installed. Otherwise, return 0.
      :return: (int)
      """
      try:
          import mpi4py
  
          return mpi4py.MPI.COMM_WORLD.Get_rank()
      except ImportError:
          return 0
  
file_path: stable-baselines/stable_baselines/common/misc_util.py
imports: import random
  import gym
  import numpy
  import tensorflow
label_desc: Use image node_id 4 for calling a global function with example usage: mpi_rank_or_zero() and returns: mpi4py, int