public void remove() {
            if (current == null)
                throw new IllegalStateException();
            if (modCount != expectedModCount)
                throw new ConcurrentModificationException();
            Object k = current.key;
            current = null;
            AntiCollisionHashMap.this.removeEntryForKey(k);
            expectedModCount = modCount;
        }
Like addEntry except that this version is used when creating entries as
part of Map construction or "pseudo-construction" (cloning,
deserialization). This version needn't worry about resizing the table.

Subclass overrides this to alter the behavior of SafelyHashMap(Map),
clone, and readObject.
src/main/java/com/alibaba/fastjson/util/AntiCollisionHashMap.java