As their children documents' total size counter will also be added to 'trash size' counter of parent document
How to reproduce:
- create a Folder 'Project'
- create another Folder 'Spec' under 'Project'
- add a File 'File 1' (with a file attached) in 'Spec'
- delete (move to trash) Folder 'Spec'
- the size of file attached to 'File 1' is added 2x in 'trash size' counter of 'Project 1'