code: def join(self):
      if self.proc is not None:
          self.proc.stdin.close()
          self.proc.stdout.close()  # avoid ResourceWarning
          self.proc.kill()
          self.proc.wait()
          self.proc = None
  
imports: from functools import lru_cache
  import os
  import re
  import shutil
  import subprocess
  import sys
  import pytest
  import pyarrow
label_desc: Use image node_id 7 for calling the GdbSession obj's underlying member method code with example usage: obj.join() without return types