return !obj.isNull() && Space.isImmortal(obj);
return !obj.isNull() && Space.isMappedObject(obj) && Space.isImmortal(obj) && Space.isMappedObject(ObjectReference.fromObject(VM_ObjectModel.getTIB(obj)));
  public static boolean mightBeTIB(ObjectReference obj)    throws InlinePragma, UninterruptiblePragma {    return !obj.isNull() && Space.isImmortal(obj);  }