I want to make a preview of a document. I found this documentation : https://doc.nuxeo.com/nxdoc/preview/

There is an example mentionned in the site : http://localhost:8080/nuxeo/site/api/v1/repo/default/id/23d871d2-052a-4f58-8f90-4b07c5a074ea/@blob/file:content/@preview/image

In the example the format is image. But what are the possible format ? For example for a .xlsx file , for a .pdf file, for .docx file