text: from h2pubsub import Client
  from eventlet.green.OpenSSL import SSL, crypto
  from eventlet import sleep
  
  
  def alpn_callback(conn, protocols):
      if b'h2' in protocols:
          return b'h2'
      raise RuntimeError('No acceptable protocol offered!')
  
  
  def npn_advertise_cb(conn):
      return [b'h2']
  
  
  context = SSL.Context(SSL.SSLv23_METHOD)
  context.set_verify(SSL.VERIFY_NONE, lambda *args: True)
  context.use_privatekey_file('server.key')
  context.use_certificate_file('server.crt')
  context.set_npn_advertise_callback(npn_advertise_cb)
  context.set_alpn_select_callback(alpn_callback)
  context.set_cipher_list('ECDHE+AESGCM')
  context.set_tmp_ecdh(crypto.get_elliptic_curve(u'prime256v1'))
  
  client = Client(address='localhost', port=443, ssl_context=context)
  
  while True:
      client.publish('/test', 'aiueo')
      sleep(0.2)
  