class_docstr: Implementation of the Communicator class via torch.distributed. Use this
  communicator to communicate between different processes, potentially,
  running on different nodes.
docstr: Sends the specified tensor to the destination dst.
code: def isend(self, tensor, dst):
      """Sends the specified tensor to the destination dst."""
      assert dist.is_initialized(), "initialize the communicator first"
      return dist.isend(tensor.data, dst, group=self.main_group)
  
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 8 for calling the DistributedCommunicator obj's underlying member method code with example usage: obj.isend(tensor, dst) and returns: dist