public function read_meta( &$object ) {
		return $this->data_store_meta->read_meta( $object );
	}

	/**
	 * Deletes meta based on meta ID.
	 *
	 * @param  WC_Data  $object WC_Data object.
	 * @param  stdClass $meta (containing at least ->id).
	 */
	public function delete_meta( &$object, $meta ) {
		return $this->data_store_meta->delete_meta( $object, $meta );
	}

	/**
	 * Add new piece of meta.
	 *
	 * @param  WC_Data  $object WC_Data object.
	 * @param  stdClass $meta (containing ->key and ->value).
	 * @return int meta ID
	 */
	public function add_meta( &$object, $meta ) {
		return $this->data_store_meta->add_meta( $object, $meta );
	}

	/**
	 * Update meta.
	 *
	 * @param  WC_Data  $object WC_Data object.
	 * @param  stdClass $meta (containing ->id, ->key and ->value).
	 */
	public function update_meta( &$object, $meta ) {
		return $this->data_store_meta->update_meta( $object, $meta );
	}

	/**
	 * Returns list of metadata that is considered "internal".
	 *
	 * @return array
	 */
	public function get_internal_meta_keys() {
		// XXX: This is mostly just to trick `WC_Data_Store_WP` for the time being.
		return array(
			'_customer_user',
			'_order_key',
			'_order_currency',
			'_billing_first_name',
			'_billing_last_name',
			'_billing_company',
			'_billing_address_1',
			'_billing_address_2',
			'_billing_city',
			'_billing_state',
			'_billing_postcode',
			'_billing_country',
			'_billing_email',
			'_billing_phone',
			'_shipping_first_name',
			'_shipping_last_name',
			'_shipping_company',
			'_shipping_address_1',
			'_shipping_address_2',
			'_shipping_city',
			'_shipping_state',
			'_shipping_postcode',
			'_shipping_country',
			'_shipping_phone',
			'_completed_date',
			'_paid_date',
			'_edit_lock',
			'_edit_last',
			'_cart_discount',
			'_cart_discount_tax',
			'_order_shipping',
			'_order_shipping_tax',
			'_order_tax',
			'_order_total',
			'_payment_method',
			'_payment_method_title',
			'_transaction_id',
			'_customer_ip_address',
			'_customer_user_agent',
			'_created_via',
			'_order_version',
			'_prices_include_tax',
			'_date_completed',
			'_date_paid',
			'_payment_tokens',
			'_billing_address_index',
			'_shipping_address_index',
			'_recorded_sales',
			'_recorded_coupon_usage_counts',
			'_download_permissions_granted',
			'_order_stock_reduced',
		);
	}

}