old_contents: # Author:  Lisandro Dalcin
  # Contact: dalcinl@gmail.com
  
  # pylint: disable=unused-import
  # pylint: disable=redefined-builtin
  # pylint: disable=missing-module-docstring
  
  try:
  
      from concurrent.futures import (
          FIRST_COMPLETED,
          FIRST_EXCEPTION,
          ALL_COMPLETED,
          CancelledError,
          TimeoutError,
          Future,
          Executor,
          wait,
          as_completed,
      )
  
      try:  # Python 3.7
          from concurrent.futures import BrokenExecutor
      except ImportError:  # pragma: no cover
          BrokenExecutor = RuntimeError
  
      try:  # Python 3.8
          from concurrent.futures import InvalidStateError
      except ImportError:  # pragma: no cover
          InvalidStateError = CancelledError.__base__
  
  except ImportError:  # pragma: no cover
  
      from ._base import (
          FIRST_COMPLETED,
          FIRST_EXCEPTION,
          ALL_COMPLETED,
          CancelledError,
          TimeoutError,
          InvalidStateError,
          BrokenExecutor,
          Future,
          Executor,
          wait,
          as_completed,
      )
  
new_contents: # Author:  Lisandro Dalcin
  # Contact: dalcinl@gmail.com
  
  # pylint: disable=unused-import
  # pylint: disable=redefined-builtin
  # pylint: disable=missing-module-docstring
  
  try:
  
      from concurrent.futures import (
          FIRST_COMPLETED,
          FIRST_EXCEPTION,
          ALL_COMPLETED,
          CancelledError,
          TimeoutError,
          Future,
          Executor,
          wait,
          as_completed,
      )
  
      try:  # Python 3.7
          from concurrent.futures import BrokenExecutor
      except ImportError:  # pragma: no cover
          class BrokenExecutor(RuntimeError):
              """The executor has become non-functional."""
  
      try:  # Python 3.8
          from concurrent.futures import InvalidStateError
      except ImportError:  # pragma: no cover
          # pylint: disable=too-few-public-methods
          # pylint: disable=useless-object-inheritance
          class InvalidStateError(CancelledError.__base__):
              """The operation is not allowed in this state."""
  
  except ImportError:  # pragma: no cover
  
      from ._base import (
          FIRST_COMPLETED,
          FIRST_EXCEPTION,
          ALL_COMPLETED,
          CancelledError,
          TimeoutError,
          InvalidStateError,
          BrokenExecutor,
          Future,
          Executor,
          wait,
          as_completed,
      )
  
subject: Fix backward compatibility exception types