common_helper/src/main/java/com/xiongyingqi/jackson/helper/ThreadJacksonMixInHolder.java
public static void addMixIns(Set<Map.Entry<Class<?>, Class<?>>> toAddMixIns) {
        ThreadJacksonMixInHolder holder = holderThreadLocal.get();
        if (holder == null) {
            holder = new ThreadJacksonMixInHolder();
            holderThreadLocal.set(holder);
        }
        if (holder.mixIns == null) {
            holder.mixIns = new HashSet<Map.Entry<Class<?>, Class<?>>>();
        }
        holder.mixIns.addAll(toAddMixIns);
    }
public static void addMixIns(Set<Map.Entry<Class<?>, Class<?>>> toAddMixIns) {
        ThreadJacksonMixInHolder holder = holderThreadLocal.get();
        if (holder == null) {
            holder = new ThreadJacksonMixInHolder();
            holderThreadLocal.set(holder);
        }
        if (holder.mixIns == null) {
            holder.mixIns = new HashSet<Map.Entry<Class<?>, Class<?>>>();
        }
        holder.mixIns.addAll(toAddMixIns);
    }
不同于setMixIns，addMixIns为增加MixIn集合到线程内，即不会清除已经保存的数据
<br>2014年4月4日 下午12:08:15

@param toAddMixIns