code: def _call_connection_lost(self, exc):
      try:
          self._protocol.connection_lost(exc)
      finally:
          # wake up futures waiting for wait()
          for waiter in self._exit_waiters:
              if not waiter.cancelled():
                  waiter.set_result(self._returncode)
          self._exit_waiters = None
          self._loop = None
          self._proc = None
          self._protocol = None
  
imports: import collections
  import subprocess
  import warnings
  from .None import protocols
  from .None import transports
  from .log import logger
label_desc: Use image node_id 21 for calling the BaseSubprocessTransport obj's underlying member method code with example usage: obj._call_connection_lost(exc) without return types