Subtask Status Validator
This validator enforces that a transition can only occur when all the individual subtask linked to the current issue are in desired status.
You are asked the provide the desired status of the subtasks in the validator configuration.
For example, if the validator above is added to the “Start Progress” transition of the Task issue type in the workflow, the issue below cannot be transitioned into the “In Progress” status, before all the subtasks are transitioned into “In Progress” status.