code: public function setCache($cache)
      {
          if (!is_bool($cache) && !$cache instanceof CacheInterface) {
              throw new Exception('Cache must be a boolean or an instance of Flintstone\Cache\CacheInterface');
          }
  
          if ($cache === true) {
              $cache = new ArrayCache();
          }
  
          $this->config['cache'] = $cache;
      }
docs: Set the cache.
  
  @param mixed $cache
  
  @throws Exception