private Validator visibleValidator(@Nonnull ImmutableTree source,
@Nonnull ImmutableTree dest) {
// TODO improve: avoid calculating the 'before' permissions in case the current parent permissions already point to the correct tree.
ImmutableTree parent = moveCtx.rootBefore.getTree("/");
TreePermission tp = getPermissionProvider().getTreePermission(parent, TreePermission.EMPTY);
for (String n : source.getPath().split("/")) {
tp = tp.getChildPermission(n, parent.getChild(n).getNodeState());
}
Validator validator = createValidator(source, dest, tp, this);
return new VisibleValidator(validator, true, false);
}