Best way to index multiple attachments?

To index a single attachment together with a page by adding a property of the Attachment type to the page model - like this - works well:
http://world.episerver.com/documentation/Items/Developers-Guide/EPiServer-Find/9/DotNET-Client-API/File-attachments/

But how to handle multiple attachments when they are dynamic in numbers?

(The reason for this question is to get a search hit on a page also from the contents of the files in a LinkItemCollection.)