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 rank of the current process.
code: def get_rank(self):
      """Returns the rank of the current process."""
      assert dist.is_initialized(), "initialize the communicator first"
      return dist.get_rank()
  
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 21 for calling the DistributedCommunicator obj's underlying member method code with example usage: obj.get_rank() and returns: dist