class_docstr: ZAP authentication for use in the tornado IOLoop
docstr: Start ZAP authentication
docstr_tok: ["Start","ZAP","authentication"]
code: def start(self):
      """Start ZAP authentication"""
      super(IOLoopAuthenticator, self).start()
      self.zap_stream = zmqstream.ZMQStream(
          self.zap_socket, self.io_loop
      )
      self.zap_stream.on_recv(self.handle_zap_message)
  
imports: from tornado import ioloop
  from zmq.eventloop import zmqstream
  from .base import Authenticator
label_desc: Use image node_id 2 for calling the IOLoopAuthenticator obj's underlying member method code with example usage: obj.start() without return types