unique_child(a_candidate)

Obtain a XFile instance reference unique name item in the folder.

If the instance's file reference is not a folder, missing value will be returned.If this methods is sent to non existing item, error number 1350 will be raised.

• a_candidate(text or list) : A candidate of a name to obtain unique item. If same name item exists, the candidate is modified.

script object : a XFile instance