Description:
identifier is a read-only property of the widget
object. It is the unique string identifier that identifies a widget after
it has been installed into a device. The string returned is the value of the Identifier key
defined in the widget property list file (info.plist).
For more information on the info.plist file, see Widget component files.
Syntax:
[String] widget.identifier
or
[String] window.widget.identifier