code: func (s tlsSniSolver) CleanUp(domain, token, keyAuth string) error {
  	_, acmeDomain, err := acme.TLSSNI01ChallengeCert(keyAuth)
  	if err != nil {
  		return err
  	}
  	uncacheCertificate(acmeDomain)
  	return nil
  }
docs: // CleanUp removes the challenge certificate from the cache.