class CustomArrayObject

class CustomArrayObject implements \ArrayAccess, \IteratorAggregate, \Countable, \Serializable {
  private $array;
  public function __construct(array $array = null) {
    $this->array = $array ?: array();
  }
  public function offsetExists($offset) {
    return array_key_exists($offset, $this->array);
  }
  public function offsetGet($offset) {
    return $this->array[$offset];
  }
  public function offsetSet($offset, $value) {
    if (null === $offset) {
      $this->array[] = $value;
    }
    else {
      $this->array[$offset] = $value;
    }
  }
  public function offsetUnset($offset) {
    unset($this->array[$offset]);
  }
  public function getIterator() {
    return new \ArrayIterator($this->array);
  }
  public function count() {
    return count($this->array);
  }
  public function serialize() {
    return serialize($this->array);
  }
  public function unserialize($serialized) {
    $this->array = (array) unserialize((string) $serialized);
  }

}