code: def onChallenge(self, challenge):
      secret = config["crossbar"]["auth"]["password"]
      signature = auth.compute_wcs(
          secret.encode("utf8"),
          challenge.extra["challenge"].encode("utf8"),
      )
  
      return signature.decode("ascii")
  
file_path: SerpentAI/serpent/wamp_components/analytics_component.py
imports: import asyncio
  from autobahn.asyncio.wamp import ApplicationSession, ApplicationRunner
  from autobahn.wamp.types import RegisterOptions, SubscribeOptions
  from autobahn.wamp import auth
  from serpent.config import config
  import aioredis
  import json
label_desc: Use image node_id 4 for calling the AnalyticsWAMPComponent obj's underlying member method code with example usage: obj.onChallenge(challenge) and returns: signature