code: public static final synchronized void start(Engine engine)
      {
          Check.notNull(engine);
  
          if (started)
          {
              throw new LionEngineException(ERROR_STARTED_ALREADY);
          }
          Verbose.info(new StringBuilder(MIN_LENGTH).append(ENGINE_STARTING)
                                                    .append(Constant.ENGINE_VERSION)
                                                    .append(Constant.QUOTE)
                                                    .append(FOR)
                                                    .append(Constant.QUOTE)
                                                    .append(engine.getName())
                                                    .append(Constant.SPACE)
                                                    .append(engine.getVersion())
                                                    .append(Constant.QUOTE)
                                                    .toString());
  
          Medias.setFactoryMedia(new FactoryMediaDefault());
  
          engine.open();
          Engine.engine = engine;
          started = true;
      }
docs: Start engine. Has to be called before anything and only one time, in the main.
  
  @param engine The engine implementation used (must not be <code>null</code>).
  @throws LionEngineException If invalid argument or the engine has already been started.