public function check_cart_item_validity() {
		$return = true;

		foreach ( $this->get_cart() as $cart_item_key => $values ) {
			$product = $values['data'];

			if ( ! $product || ! $product->exists() || 'trash' === $product->get_status() ) {
				$this->set_quantity( $cart_item_key, 0 );
				$return = new WP_Error( 'invalid', __( 'An item which is no longer available was removed from your cart.', 'woocommerce' ) );
			}
		}

		return $return;
	}