code: @SuppressWarnings("unchecked")
      public <T> T lookup(final String id) {
          for (final IdentifiableController controller : identifiables) {
              if(controller.getId().equals(id)) {
                  return (T) controller;
              }
          }
          throw new IllegalArgumentException("Could not find a controller with the ID '" + id + "'");
      }
docs: Returns a controller instance with the given ID.
  
  @param id
  The string ID of the controller as returned by
  {@link IdentifiableController#getId()}
  @return
  The controller with the given ID that has just been
  looked up.
  @throws IllegalArgumentException
  thrown if a controller cannot be found with the given ID.