public void putAll(Map<? extends K, ? extends V> m) {
        Iterator var2 = m.entrySet().iterator();

        while(var2.hasNext()) {
            Map.Entry<? extends K, ? extends V> entry = (Map.Entry)var2.next();
            this.put(entry.getKey(), entry.getValue());
        }

    }
copy & modify org.redisson.misc.BiHashMap
https://github.com/redisson/redisson/blob/master/redisson/src/main/java/org/redisson/misc/BiHashMap.java
@param <K>
@param <V>
agent-module/profiler-test/src/main/java/com/navercorp/pinpoint/profiler/test/util/BiHashMap.java