Folder part

Can someone show me a picture of what a folder part is? How can I create a folder part?

Manual p.79
A folder part is a graphic representation of events and parts on the tracks in the folder. Folder parts indicate the position and length of the events and parts, as well as on which track they are (their vertical position). If part colors are used, these are also shown in the folder part.

Thanks

You can look for yourself if you want to. Create a folder track in one of your projects. Drag some tracks into the folder and you will see what happens to the foldertrack.

Right Click, add folder track?