A new version of System was added to project The Inbox:
http://source.squeak.org/inbox/System-ct.1118.mcz

==================== Summary ====================

Name: System-ct.1118
Author: ct
Time: 26 October 2019, 9:53:56.908469 pm
UUID: 813aa07b-dde6-7f46-af06-552f9f2f1b37
Ancestors: System-mt.1116

Adds execute-around utility to change an AppRegistry default temporarily

"Usage:"
SoundService setDefault: DummySoundSystem new during: [SoundService beep]

=============== Diff against System-mt.1116 ===============

Item was added:
+ ----- Method: AppRegistry class>>setDefault:during: (in category 'defaults') -----
+ setDefault: aClassOrNil during: aBlock
+ 
+ 	| previousDefault |
+ 	previousDefault := self default.
+ 	self default: aClassOrNil.
+ 	^ aBlock ensure: [
+ 		self default: previousDefault]!