class_docstr: Pushes chunks of files to our streaming endpoint.
  
  This class is used as a singleton. It has a thread that serializes access to
  the streaming endpoint and performs rate-limiting and batching.
  
  TODO: Differentiate between binary/text encoding.
code: def start(self) -> None:
      self._init_endpoint()
      self._thread.start()
  
imports: import base64
  import functools
  import itertools
  import logging
  import os
  import queue
  import random
  import sys
  import threading
  import time
  from types import TracebackType
  from typing import TYPE_CHECKING, Any, Callable, Dict, List, NamedTuple, Optional, Set, Tuple, Type, Union
  import requests
  import wandb
  from wandb import util
  from wandb.sdk.internal import internal_api
  from ..lib import file_stream_utils
label_desc: Use image node_id 3 for calling the FileStreamApi obj's underlying member method code with example usage: obj.start() without return types