text: from autobahn.twisted.component import Component, run
  # or: from autobahn.asyncio.component import Component, run
  from twisted.internet.defer import inlineCallbacks
  
  demo = Component(
      transports=[
          {
              "url": "wss://demo.crossbar.io/ws",
          }
      ],
      realm="crossbardemo",
  )
  
  # 1. subscribe to a topic
  @demo.subscribe('io.crossbar.demo.hello')
  def hello(msg):
      print("Got hello: {}".format(msg))
  
  
  # 2. register a procedure for remote calling
  @demo.register('io.crossbar.demo.add2')
  def add2(x, y):
      return x + y
  
  
  # 3. after we've authenticated, run some code
  @demo.on_join
  async def joined(session, details):
      # publish an event (won't go to "this" session by default)
      session.publish('io.crossbar.demo.hello', 'Hello, world!')
  
      # 4. call a remote procedure
      result = await session.call('io.crossbar.demo.add2', 2, 3)
      print("io.crossbar.demo.add2(2, 3) = {}".format(result))
  
      await session.leave()
  
  if __name__ == "__main__":
      run([demo])
  