code: public List<Entity> weakEntities(Entity e) {
          final List<Entity> res = new ArrayList<Entity>();
          for (Entity entity : getEntities().values()) {
              if (entity.getOwner() != null && entity.getOwner().getEntityId().compareTo(e.getId()) == 0) {
                  res.add(entity);
              }
          }
          if (res.isEmpty()) {
              return null;
          } else {
              return res;
          }
      }
docs: Return the list of weak entities of the given entity.
  
  @param e The strong entity
  @return The list of weak entities