code: public <T extends Entity> T byID(Class<T> clazz, AssetID id) {
          return instance.getWrapperManager().create(clazz, id, true);
      }
docs: Returns an Entity of Type T with the given ID or null if the ID is
  invalid.
  
  @param <T>   Entity Type to retrieve.
  @param clazz - T Class.
  @param id    ID of the Entity to retrieve.
  @return an instance of an Entity of Type T or null if ID is invalid.