嵌套类引用实例化的外部类的方法

public class HashMap<K,V>
extends AbstractMap<K,V>
implements Map<K,V>, Cloneable, Serializable
{
...
final Entry<K,V> removeEntryForKey(Object key) {...}
private abstract class HashIterator<E> implements Iterator<E> {
Entry<K,V> next;    // next entry to return
int expectedModCount;    // For fast-fail
int index;        // current slot
Entry<K,V> current;    // current entry

HashIterator() {...}

public final boolean hasNext() {...}

final Entry<K,V> nextEntry() {...}

public void remove() {
if (current == null)
throw new IllegalStateException();
if (modCount != expectedModCount)
throw new ConcurrentModificationException();
Object k = current.key;
current = null;
HashMap.this.removeEntryForKey(k);
expectedModCount = modCount;
}
}
}