old_contents: import sys
  
  from .client import Client
  from .middleware import WSGIApp, Middleware
  from .server import Server
  if sys.version_info >= (3, 5):  # pragma: no cover
      from .asyncio_server import AsyncServer
      from .asyncio_client import AsyncClient
      from .async_drivers.asgi import ASGIApp
      try:
          from .async_drivers.tornado import get_tornado_handler
      except ImportError:
          get_tornado_handler = None
  else:  # pragma: no cover
      AsyncServer = None
      AsyncClient = None
      get_tornado_handler = None
      ASGIApp = None
  
  __all__ = ['__version__', 'Server', 'WSGIApp', 'Middleware', 'Client']
  if AsyncServer is not None:  # pragma: no cover
      __all__ += ['AsyncServer', 'ASGIApp', 'get_tornado_handler',
                  'AsyncClient'],
  
new_contents: import sys
  
  from .client import Client
  from .middleware import WSGIApp, Middleware
  from .server import Server
  if sys.version_info >= (3, 5):  # pragma: no cover
      from .asyncio_server import AsyncServer
      from .asyncio_client import AsyncClient
      from .async_drivers.asgi import ASGIApp
      try:
          from .async_drivers.tornado import get_tornado_handler
      except ImportError:
          get_tornado_handler = None
  else:  # pragma: no cover
      AsyncServer = None
      AsyncClient = None
      get_tornado_handler = None
      ASGIApp = None
  
  __all__ = ['Server', 'WSGIApp', 'Middleware', 'Client']
  if AsyncServer is not None:  # pragma: no cover
      __all__ += ['AsyncServer', 'ASGIApp', 'get_tornado_handler',
                  'AsyncClient'],
  
subject: Remove unused __version__ constant (Fixes #262)