silverstripe-framework/tests/filesystem/FileMigrationHelperTest.yml

SilverStripe\Assets\Folder:
  parent:
    Name: ParentFolder
  subfolder:
    Name: SubFolder
    Parent: =>SilverStripe\Assets\Folder.parent
SilverStripe\Assets\Image:
  image1:
    Name: myimage.jpg
  image2:
    Name: myimage.jpg
    ParentID: =>SilverStripe\Assets\Folder.subfolder
SilverStripe\Assets\File:
  file1:
    Name: anotherfile.jpg
  file2:
    Name: file.jpg
    ParentID: =>SilverStripe\Assets\Folder.parent
  file3:
    Name: picture.jpg
    ParentID: =>SilverStripe\Assets\Folder.subfolder