+ /**
+ * @see GenericArrayObject::getSerializationData
+ *
+ * @since 1.21
+ *
+ * @return array
+ */
+ protected function getSerializationData() {
+ return array_merge(
+ parent::getSerializationData(),
+ array(
+ 'internalIds' => $this->byInternalId,
+ 'globalIds' => $this->byGlobalId,
+ )
+ );
+ }
+
+ /**
+ * @see GenericArrayObject::unserialize
+ *
+ * @since 1.21
+ *
+ * @param string $serialization
+ *
+ * @return array
+ */
+ public function unserialize( $serialization ) {
+ $serializationData = parent::unserialize( $serialization );
+
+ $this->byInternalId = $serializationData['internalIds'];
+ $this->byGlobalId = $serializationData['globalIds'];
+
+ return $serializationData;
+ }
+