Persists the object and, when the target is a collection, lists it there; a collection takes an object
with no parent as its own. Any other target files the object itself, so there is nothing to list.
Throws, before persisting anything, when the collection refuses the object.
Persists the object and, when the target is a collection, lists it there; a collection takes an object with no parent as its own. Any other target files the object itself, so there is nothing to list. Throws, before persisting anything, when the collection refuses the object.