code: public Set<Session> findSessionsByIP(final String ip) {
      final Set<Session> ret = new HashSet<>();
  
      final Map<String, Session> cacheSnapshot = this.cache.asMap();
      for (final Entry<String, Session> entry : cacheSnapshot.entrySet()) {
        if (entry.getValue().getIp().equals(ip)) {
          ret.add(entry.getValue());
        }
      }
  
      return ret;
    }
docs: Returns sessions whose IP equals to the given IP.