code: def __init__(self):
      emulator_path = _get_cbt_emulator_path()
      self._emulator = subprocess.Popen(
          [emulator_path, "-port", "0"],
          stdout=subprocess.PIPE,
          stderr=subprocess.DEVNULL,
          bufsize=0,
      )
      out = self._emulator.stdout
      self._emulator_addr = _extract_emulator_addr_from_output(out)
      self._output_reading_thread = Thread(target=out.read)
      self._output_reading_thread.start()
  
file_path: io/tests/test_bigtable/bigtable_emulator.py
imports: import os
  import subprocess
  import re
  import tensorflow
  from threading import Thread
  from typing import List
label_desc: Use image node_id 1 to create a new BigtableEmulator object  with example: obj = BigtableEmulator()