DowncastReduceChangesEvent

Fired to enable reducing (transforming) changes buffered in the Differ before convertChanges() will fire any conversion events.

For instance, a feature can replace selected DifferItems with a reinsert entry to trigger reconversion of an element when e.g. its attribute has changes. The * DowncastHelpers.elementToStructure() helper is using this event to trigger reconversion of an element when the element, its attributes or direct children changed.