I keep getting errors for
if (Objects.isNull(region)) {

and
if (Objects.isNull(regionObjects)) {

Eclipse says that they are undefined for the type objects.

public static boolean isWorldObject(int id, int x, int y, int height) {
Region region = getRegion(x, y);
if (Objects.isNull(region)) {
return true;
}
Collection<WorldObject> regionObjects = worldObjects.get(region.id);
if (Objects.isNull(regionObjects)) {
return true;
}