Need file signature of bsdesign

I accidentally delete bsdesign file.

I am in pursuit of recovering it.

My first step is to search it using testdisk and hope I can find it.

But turn out the bsdesign file is kind of binary thing.

So, I am planning to narrow it down by file signature.

Am I on the right path?

Please give me hints.

The alternative solution is welcome.

Status:

 1. The file was placed in LVM partition. 
 2. The partition is in ext4 format.
 3. Deleted using rm command.
 4. Wondering if the application has some sort of cache, or snapshot.
 5. I have restarted the computer multiple times.