code: def connect(self, topic, cb):
          
          arr = self._connects.setdefault(topic, [])
          arr.append(cb)
          return {'topic': topic, 'cb': cb}
docs: Registers a callback for an event topic. Valid topics and their
          associated values:
  
          started-utterance: name=<str>
          started-word: name=<str>, location=<int>, length=<int>
          finished-utterance: name=<str>, completed=<bool>
          error: name=<str>, exception=<exception>
  
          @param topic: Event topic name
          @type topic: str
          @param cb: Callback function
          @type cb: callable
          @return: Token to use to unregister
          @rtype: dict