code: private ApplicationContext loadStartupContext(Class<? extends SplashScreenConfig> startupConfig) {
          if(startupConfig == null)
              return null;
          logger.info("Loading startup context from class ("
                      + startupConfig.getName()
                      + ")");
          return new AnnotationConfigApplicationContext(startupConfig);
      }
docs: Returns an application context loaded from the bean definition file at
  the given classpath-relative location.
  
  @return An application context loaded from the given location, or null if
  {@code startupContextPath} is null or empty.