class_docstr: Run tests in a subprocess
      
class_docstr_tok: ["Run","tests","in","a","subprocess"]
code: def launch(self, buffer_output=False, capture_output=False):
      # print('*** ENV:', self.env)  # dbg
      # print('*** CMD:', self.cmd)  # dbg
      env = os.environ.copy()
      env.update(self.env)
      if buffer_output:
          capture_output = True
      self.stdout_capturer = c = StreamCapturer(echo=not buffer_output)
      c.start()
      stdout = c.writefd if capture_output else None
      stderr = subprocess.STDOUT if capture_output else None
      self.process = subprocess.Popen(
          self.cmd, stdout=stdout, stderr=stderr, env=env
      )
  
imports: from __future__ import print_function
  import argparse
  import json
  import multiprocessing.pool
  import os
  import stat
  import re
  import requests
  import shutil
  import signal
  import sys
  import subprocess
  import time
  from .iptest import have, test_group_names, test_sections, StreamCapturer, test_for
  from IPython.utils.path import compress_user
  from IPython.utils.py3compat import bytes_to_str
  from IPython.utils.sysinfo import get_sys_info
  from IPython.utils.tempdir import TemporaryDirectory
  from IPython.utils.text import strip_ansi
label_desc: Use image node_id 3 for calling the TestController obj's underlying member method code with example usage: obj.launch(buffer_output, capture_output) without return types