old_contents: """Abstract base classes."""
  import sys
  from abc import ABCMeta, abstractmethod
  
  
  class ACommand(metaclass=ABCMeta):
  
      """Abstract base class for tangled commands."""
  
      def __init__(self, parser, args):
          self.parser = parser
          self.args = args
  
      @classmethod
      @abstractmethod
      def configure(cls, parser):
          raise NotImplementedError()
  
      @abstractmethod
      def run(self):
          raise NotImplementedError()
  
      def print_error(self, *args, file=sys.stderr, **kwargs):
          print(*args, file=file, **kwargs)
  
      def exit(self, message=None, status=1):
          """Exit with error code by default.
  
          If ``message`` is passed, it will be printed to stderr.
  
          """
          if message:
              if status == 0:
                  print(message)
              else:
                  self.print_error(message)
          sys.exit(status)
  
new_contents: """Abstract base classes."""
  import sys
  from abc import ABCMeta, abstractmethod
  
  
  class ACommand(metaclass=ABCMeta):
  
      """Abstract base class for tangled commands."""
  
      def __init__(self, parser, args):
          self.parser = parser
          self.args = args
  
      @classmethod
      @abstractmethod
      def configure(cls, parser):
          raise NotImplementedError()
  
      @abstractmethod
      def run(self):
          raise NotImplementedError()
  
      def print_error(self, *args, file=sys.stderr, **kwargs):
          print(*args, file=file, **kwargs)
  
subject: Remove ACommand.exit()