### Question:
ParamFlowRuleUtil { public static boolean isValidRule(ParamFlowRule rule) { return rule != null && !StringUtil.isBlank(rule.getResource()) && rule.getCount() >= 0 && rule.getGrade() >= 0 && rule.getParamIdx() != null && rule.getBurstCount() >= 0 && rule.getControlBehavior() >= 0 && rule.getDurationInSec() > 0 && rule.getMaxQueueingTimeMs() >= 0 && checkCluster(rule); } private  ParamFlowRuleUtil(); static boolean isValidRule(ParamFlowRule rule); static boolean validClusterRuleId(Long id); static void fillExceptionFlowItems(ParamFlowRule rule); static Map<String, List<ParamFlowRule>> buildParamRuleMap(List<ParamFlowRule> list); static Map<String, List<ParamFlowRule>> buildParamRuleMap(List<ParamFlowRule> list,
                                                                     Predicate<ParamFlowRule> filter); static Map<String, List<ParamFlowRule>> buildParamRuleMap(List<ParamFlowRule> list,
                                                                     Predicate<ParamFlowRule> filter,
                                                                     boolean shouldSort); static Map<K, List<ParamFlowRule>> buildParamRuleMap(List<ParamFlowRule> list,
                                                                    Function<ParamFlowRule, K> groupFunction,
                                                                    Predicate<ParamFlowRule> filter,
                                                                    boolean shouldSort);  }### Answer:
@Test public void testCheckValidHotParamRule() { ParamFlowRule rule1 = new ParamFlowRule(); ParamFlowRule rule2 = new ParamFlowRule(""); assertFalse(ParamFlowRuleUtil.isValidRule(null)); assertFalse(ParamFlowRuleUtil.isValidRule(rule1)); assertFalse(ParamFlowRuleUtil.isValidRule(rule2)); ParamFlowRule rule3 = new ParamFlowRule("abc") .setCount(-1) .setParamIdx(1); assertFalse(ParamFlowRuleUtil.isValidRule(rule3)); ParamFlowRule rule4 = new ParamFlowRule("abc") .setCount(1); ParamFlowRule rule5 = new ParamFlowRule("abc") .setCount(1) .setParamIdx(-1); assertFalse(ParamFlowRuleUtil.isValidRule(rule4)); assertTrue(ParamFlowRuleUtil.isValidRule(rule5)); ParamFlowRule goodRule = new ParamFlowRule("abc") .setCount(10) .setParamIdx(1); assertTrue(ParamFlowRuleUtil.isValidRule(goodRule)); }