§81's "UI controls": a named UIControlRegistry of widget
constructors.
Not revocable — the registry has no removal, so a plugin that registered
a control has no way to take it back. UIControlRegistry.register
of the identical constructor is a no-op; a different constructor under
the same name throws.
§81's "UI controls": a named UIControlRegistry of widget constructors.
Not revocable — the registry has no removal, so a plugin that registered a control has no way to take it back. UIControlRegistry.register of the identical constructor is a no-op; a different constructor under the same name throws.