code: def __init__(self, q: janus.Queue):
      super().__init__()
      self._q = q
      self._saw_eos = False
      self._closed = False
      self._unread = memoryview(b"")
      self._off = 0
  
imports: from typing import BinaryIO, List, Optional, Tuple, Type
  from types import TracebackType
  import abc
  import io
  import os
  import sys
  from concurrent.futures import ThreadPoolExecutor
  import janus
  from hailtop.utils import blocking_to_async
  from .exceptions import UnexpectedEOFError
label_desc: Use image node_id 1 to create a new BlockingQueueReadableStream object from inherited base classes: io, _Closable with example: obj = BlockingQueueReadableStream(q)