* a different type that the caller can use to reproduce the execution of the rule. This object is the one
 * that is going to be cached, and most likely the thing the caller really cares about
 */
public interface CachingRuleExecutor<KEY, DETAILS, RESULT> {
    /**
     * Executes a rule, fetching the result from the cache if available, or executing the rule and caches
     * the result in case of cache miss.
     *  @param rule the rule to be executed