code: public Optional<OutputControllerModel> getOutputController(Identifiable identifiable) {
          return outputControllers.stream()
                  .filter(outputController ->  outputController.getID().equals(identifiable.getID()))
                  .findFirst();
      }
docs: Returns a {@link Optional} object that may or may not contain the desired {@link OutputControllerModel},
  depending on whether it was registered with Izou or not.
  
  @param identifiable The ID of the OutputController that should be retrieved.
  @return The {@link Optional} object that may or may not contain the desired {@link OutputControllerModel},
  depending on whether it was registered with Izou or not.