class_docstr: Implementation of the Communicator class via torch.distributed. Use this
  communicator to communicate between different processes, potentially,
  running on different nodes.
docstr: Returns the size of the world.
code: def get_world_size(self):
      """Returns the size of the world."""
      assert dist.is_initialized(), "initialize the communicator first"
      return self.world_size
  
imports: import logging
  import os
  import pickle
  import random
  import string
  import numpy
  import torch
  import torch.distributed
  from crypten.common import serial
  from torch.distributed import ReduceOp
  from .communicator import _logging, Communicator
label_desc: Use image node_id 20 for calling the DistributedCommunicator obj's underlying member method code with example usage: obj.get_world_size() and returns: self