message: Cache keys of challenges with associated coding challenges
  (bug causes response to add keys again with every request
  resulting in self-DoS by CTF extension test suite and possibly
  when reloading Score Board very often.)
diff: @@ -139,10 +139,12 @@ exports.serveCodeSnippet = () => async (req: Request<SnippetRequestBody, {}, {}>
  }
  exports.challengesWithCodeSnippet = () => async (req: Request, res: Response, next: NextFunction) => { // TODO Split off function for actual detection and reuse in codingChallengeFixesSpec
  + if (!cache.codingChallenges) {
  const match = /vuln-code-snippet start .*/
  const matches = await fileSniff(SNIPPET_PATHS, match)
  - const challenges = matches.map(m => m.match.trim().substr(26).trim()).join(' ').split(' ').filter(c => c.endsWith('Challenge'))
  - res.json({ challenges })
  + cache.codingChallenges = matches.map(m => m.match.trim().substr(26).trim()).join(' ').split(' ').filter(c => c.endsWith('Challenge'))
  + }
  + res.json({ challenges: cache.codingChallenges })
  }
  export const getVerdict = (vulnLines: number[], selectedLines: number[]) => {
  