old_contents: """
    HTTP2 Test Server. Highly experimental work in progress.
  """
  import argparse
  import logging
  import twisted
  import twisted.internet
  import twisted.internet.endpoints
  import twisted.internet.reactor
  
  import http2_base_server
  import test_goaway
  import test_max_streams
  import test_ping
  import test_rst_after_data
  import test_rst_after_header
  import test_rst_during_data
  
  _TEST_CASE_MAPPING = {
    'rst_after_header': test_rst_after_header.TestcaseRstStreamAfterHeader,
    'rst_after_data': test_rst_after_data.TestcaseRstStreamAfterData,
    'rst_during_data': test_rst_during_data.TestcaseRstStreamDuringData,
    'goaway': test_goaway.TestcaseGoaway,
    'ping': test_ping.TestcasePing,
    'max_streams': test_max_streams.TestcaseSettingsMaxStreams,
  }
  
  class H2Factory(twisted.internet.protocol.Factory):
    def __init__(self, testcase):
      logging.info('Creating H2Factory for new connection.')
      self._num_streams = 0
      self._testcase = testcase
  
    def buildProtocol(self, addr):
      self._num_streams += 1
      logging.info('New Connection: %d' % self._num_streams)
      if not _TEST_CASE_MAPPING.has_key(self._testcase):
        logging.error('Unknown test case: %s' % self._testcase)
        assert(0)
      else:
        t = _TEST_CASE_MAPPING[self._testcase]
  
      if self._testcase == 'goaway':
        return t(self._num_streams).get_base_server()
      else:
        return t().get_base_server()
  
  if __name__ == "__main__":
    logging.basicConfig(format = "%(levelname) -10s %(asctime)s %(module)s:%(lineno)s | %(message)s", level=logging.INFO)
    parser = argparse.ArgumentParser()
    parser.add_argument("test")
    parser.add_argument("port")
    args = parser.parse_args()
    if args.test not in _TEST_CASE_MAPPING.keys():
      logging.error('unknown test: %s' % args.test)
    else:
      endpoint = twisted.internet.endpoints.TCP4ServerEndpoint(twisted.internet.reactor, int(args.port), backlog=128)
      endpoint.listen(H2Factory(args.test))
      twisted.internet.reactor.run()
  
new_contents: """
    HTTP2 Test Server. Highly experimental work in progress.
  """
  import argparse
  import logging
  import twisted
  import twisted.internet
  import twisted.internet.endpoints
  import twisted.internet.reactor
  
  import http2_base_server
  import test_goaway
  import test_max_streams
  import test_ping
  import test_rst_after_data
  import test_rst_after_header
  import test_rst_during_data
  
  _TEST_CASE_MAPPING = {
    'rst_after_header': test_rst_after_header.TestcaseRstStreamAfterHeader,
    'rst_after_data': test_rst_after_data.TestcaseRstStreamAfterData,
    'rst_during_data': test_rst_during_data.TestcaseRstStreamDuringData,
    'goaway': test_goaway.TestcaseGoaway,
    'ping': test_ping.TestcasePing,
    'max_streams': test_max_streams.TestcaseSettingsMaxStreams,
  }
  
  class H2Factory(twisted.internet.protocol.Factory):
    def __init__(self, testcase):
      logging.info('Creating H2Factory for new connection.')
      self._num_streams = 0
      self._testcase = testcase
  
    def buildProtocol(self, addr):
      self._num_streams += 1
      logging.info('New Connection: %d' % self._num_streams)
      if not _TEST_CASE_MAPPING.has_key(self._testcase):
        logging.error('Unknown test case: %s' % self._testcase)
        assert(0)
      else:
        t = _TEST_CASE_MAPPING[self._testcase]
  
      if self._testcase == 'goaway':
        return t(self._num_streams).get_base_server()
      else:
        return t().get_base_server()
  
  if __name__ == '__main__':
    logging.basicConfig(
      format='%(levelname) -10s %(asctime)s %(module)s:%(lineno)s | %(message)s',
      level=logging.INFO)
    parser = argparse.ArgumentParser()
    parser.add_argument('--test_case', choices=sorted(_TEST_CASE_MAPPING.keys()),
      help='test case to run', required=True)
    parser.add_argument('--port', type=int, default=8080,
      help='port to run the server (default: 8080)')
    args = parser.parse_args()
    logging.info('Running test case %s on port %d' % (args.test_case, args.port))
    endpoint = twisted.internet.endpoints.TCP4ServerEndpoint(
      twisted.internet.reactor, args.port, backlog=128)
    endpoint.listen(H2Factory(args.test_case))
    twisted.internet.reactor.run()
  
subject: Modify HTTP/2 test server to display a list of available test cases and accept non-positional arguments.