Implement Placeholder
Registered by
Rico Lin
POC: https:/
This PB is about improving validation process from heat. By introduction a
placeholder, we can prevent any intended `None` as a return value to cause unexpected behaviors.
Also placeholder can record any validation we done with that value. This might help with reducing
duplicated validation.
Whiteboard
Gerrit topic: https:/
Addressed by: https:/
Implement Placeholder
(?)
