class MapEntry implements Map.Entry<K, V> {

    @Override
    @SuppressWarnings("unchecked")
    public boolean equals(Object o) {
        if (o != null && o instanceof Map.Entry) {
            Map.Entry<K, V> entry = (Map.Entry<K, V>) o;
            return (this.getKey() == null ? entry.getKey() == null : this
                    .getKey().equals(entry.getKey()))
                    && (this.getValue() == null ? entry.getValue() == null
                            : this.getValue().equals(entry.getValue()));
        }
        return false;
    }

    public  MapEntry(K key, V value, boolean modifiable);

}