common_helper/src/main/java/com/xiongyingqi/jackson/helper/ThreadJacksonMixInHolder.java
public static Set<Map.Entry<Class<?>, Class<?>>> getMixIns() {
        ThreadJacksonMixInHolder holder = holderThreadLocal.get();
        return holder.mixIns;
    }
public static Set<Map.Entry<Class<?>, Class<?>>> getMixIns() {
        ThreadJacksonMixInHolder holder = holderThreadLocal.get();
        return holder.mixIns;
    }
获取线程内的MixIn集合<p></p>
<b>注意：为了防止线程执行完毕之后仍然存在有数据，请务必适时调用clear()方法</b>

@return
@see com.xiongyingqi.jackson.helper.ThreadJacksonMixInHolder#builderMapper()
@see com.xiongyingqi.jackson.helper.ThreadJacksonMixInHolder#builderCodehausMapper()
@see com.xiongyingqi.jackson.helper.ThreadJacksonMixInHolder#clear()