if (size != 0) {
// Note: it is okay to leak changes, we must never leak mutable subtrees.
listener.onDataTreeChanged(changes, ImmutableMap.copyOf(subtrees));
if (size != 0) {
// Note: it is okay to leak changes, we must never leak mutable subtrees.
listener.onDataTreeChanged(changes, ImmutableMap.copyOf(subtrees));