You can use
rmlogotest.exe (the Restart Manager Logo Test Tool). This freeware utility, written by Microsoft, is part of the Windows App Certification Kit.
To get the latest version of the Windows App Certification Kit, download and run the Windows SDK installer. (You can find the latest Windows SDK installer by doing a Google search.) Uncheck all the boxes except for the Windows App Certification Kit box. Wait for the kit to be downloaded and installed. If I recall correctly, the kit is a couple hundred megabytes.
rmlogotest.exe will probably be in
C:\Program Files (x86)\Windows Kits\10\App Certification Kit if you're using version 10 of the Windows SDK.
Open a command prompt. Change to the correct directory. Enter
rmlogotest then a space then the process's process ID number.
If the process is "Restart Manager aware",
rmlogotest will gracefully restart it and tell you "Logo Validation Passed". Otherwise,
rmlogotest will ask it to gracefully terminate, then may tell you "Logo Validation Failed".
I tried using
rmlogotest.exe to terminate Notepad, and it worked as expected. Notepad asked me whether or not I wanted to save the unsaved text which I'd entered.
(In case you wonder what Restart Manager is and does, let me explain. Restart Manager is part of Windows, and is used by Windows Installer 4.0 and up. When Windows Installer needs to overwrite or delete an open file, it uses a three-step process. It tells Restart Manager to gracefully end the process which is using the file. It overwrites the file. Then it tells Restart Manager to start the process again.)