old_contents: def pytest_addoption(parser):
      parser.addoption('--fast', action='store_true', help="don't run slow tests")
  
  
  SIMPLE_APP = {
      'app.py': """\
  from aiohttp import web
  
  async def hello(request):
      return web.Response(text='hello world')
  
  def create_app(loop):
      app = web.Application(loop=loop)
      app.router.add_get('/', hello)
      return app"""
  }
  
  
  def get_slow(_pytest):
      return _pytest.mark.skipif(_pytest.config.getoption('--fast'), reason='not run with --fast flag')
  
  
  def get_if_boxed(_pytest):
      return _pytest.mark.skipif(not _pytest.config.getoption('--boxed'), reason='only run with --boxed flag')
  
new_contents: def pytest_addoption(parser):
      try:
          parser.addoption('--fast', action='store_true', help="don't run slow tests")
      except ValueError:
          # --fast is already defined by aiohttp
          pass
  
  
  SIMPLE_APP = {
      'app.py': """\
  from aiohttp import web
  
  async def hello(request):
      return web.Response(text='hello world')
  
  def create_app(loop):
      app = web.Application(loop=loop)
      app.router.add_get('/', hello)
      return app"""
  }
  
  
  def get_slow(_pytest):
      return _pytest.mark.skipif(_pytest.config.getoption('--fast'), reason='not run with --fast flag')
  
  
  def get_if_boxed(_pytest):
      return _pytest.mark.skipif(not _pytest.config.getoption('--boxed'), reason='only run with --boxed flag')
  
subject: resolve conflict with aiohttp master '--fast' option