code: def get_tcp_init_method(
      *,
      world_size: Optional[int] = None,
      rank: Optional[int] = None,
      hostname: Optional[str] = None,
      port: Optional[int] = None,
  ) -> str:
      """Gets init method for the TCP protocol for the distributed environment.
      For more information, see here: https://pytorch.org/docs/stable/distributed.html#tcp-initialization.
  
      Args:
          world_size: global number of workers. If ``None``, the default is fetched using :function:`get_world_size`.
          rank: Global rank of the worker calling the function. If ``None``, the default is fetched using :function:`get_global_rank`.
          hostname: an address that belongs to the rank 0 process. If ``None``, then ``localhost`` is used.
          port: A free port to use for communication. If ``None``, this port is automatically selected.
      """
      world_size = (
          world_size if world_size is not None else get_world_size()
      )
      rank = rank if rank is not None else get_global_rank()
      _validate_global_rank_world_size(world_size, rank)
      host_addr = hostname if hostname is not None else "localhost"
      host_port = port if port is not None else get_free_port()
      init_method = f"tcp://{host_addr}:{host_port}?world_size={world_size}&rank={rank}"
      return init_method
  
imports: import os
  import tempfile
  from functools import wraps
  from typing import Any, Callable, cast, List, Optional, TypeVar, Union
  import torch
  import torch.distributed
  import torch.nn.functional
  from torch import Tensor
  from torch.distributed.elastic.utils.distributed import get_free_port
  from typing_extensions import Literal
label_desc: Use image node_id 10 for calling a global function with example usage: get_tcp_init_method() and returns: init_method