ntf(
			// translators: %s is an email address.
			__( 'Billing email updated to %s.', 'woocommerce' ),
			esc_html( $email )
		);
	}

	/**
	 * Check if a given order has any partial refunds.
	 *
	 * Based on heuristics in the `wc_create_refund()` function.
	 *
	 * @param WC_Order $order An order object.
	 *
	 * @return bool
	 */
	private function order_is_partially_refunded( WC_Order $order ): bool {
		$remaining_amount = $order->get_remaining_refund_amount();
		$remaining_items  = $order->get_remaining_refund_items();
		$refunds          = $order->get_refunds();
		$last_refund      = reset( $refunds );

		// phpcs:disable WooCommerce.Commenting.CommentHooks.MissingSinceComment
		/** This filter is documented in includes/wc-order-functions.php */
		$partially_refunded = apply_filters(
			'woocommerce_order_is_partially_refunded',
			count( $refunds ) > 0 && ( $remaining_amount > 0 || ( $order->has_free_item() && $remaining_items > 0 ) ),
			$order->get_id(),
			$last_refund ? $last_refund->get_id() : 0
		);

		return (bool) $partially_refunded;
	}
}