code: def stop(self, signal=None):
          
          signal = signal or self.int_signal
          self.out.log("Cleaning up local Heroku process...")
          if self._process is None:
              self.out.log("No local Heroku process was running.")
              return
  
          try:
              os.killpg(os.getpgid(self._process.pid), signal)
              self.out.log("Local Heroku process terminated.")
          except OSError:
              self.out.log("Local Heroku was already terminated.")
              self.out.log(traceback.format_exc())
          finally:
              self._process = None
docs: Stop the heroku local subprocess and all of its children.