Problem

Accidently, the file x.pdf which was a book with a lot of annotations created by Okular is deleted. Annotations, however, are present in /home/user/.var/app/org.kde.okular/data/okular/docdata/. I have the raw file (annotation-less file) of x.pdf.

Question

How to associate existing annotations with the raw x.pdf?

Problem Details

Actually I didn't delete the file myself; I was reading the book, I added some annotations as usual; when I wanted to save the changes, Okular hanged up; I closed it, then the file was not there in its directory....it got completely disappeared.

Tested Workarounds

I have used testdisk; it doesn't found anything as my partition is NTFS. Therefore I used ntfsundelete which also was unsuccessfull, i.e. it didn't find my deleted file.