OptionalleafConfig: TreeLeafConfigReadonlyBranchThe branch configuration that will be used
Set to true to cancel the operation
OptionalCancelOptional reason for cancellation (for logging/debugging)
Optional ReadonlyLeafThe leaf configuration that will be used (if any)
OptionalModifiedSet to modify the extra filter for branches
OptionalModifiedSet to modify the extra filter for leaves
ReadonlyTimestampTimestamp when event was raised
ReadonlyTreeThe tree component that raised the event
Fired before data load - can be canceled or configs modified