code: @Test public void filterReegistrationBeansSkipsRegisteredFilters() throws Exception {
    addEmbeddedServletContainerFactoryBean();
    Filter filter=mock(Filter.class);
    FilterRegistrationBean initializer=new FilterRegistrationBean(filter);
    this.context.registerBeanDefinition("initializerBean",beanDefinition(initializer));
    this.context.registerBeanDefinition("filterBean",beanDefinition(filter));
    this.context.refresh();
    ServletContext servletContext=getEmbeddedServletContainerFactory().getServletContext();
    verify(servletContext,atMost(1)).addFilter(anyString(),(Filter)anyObject());
  }
  