code: private void configureHandlerMappings() {
          Map<String, HandlerMapping> handlerMappings = this.factory.getBeansOfType(HandlerMapping.class);
          if (handlerMappings.isEmpty()) {
              defineBean(BeanNameUrlHandlerMapping.class);
              defineBean(RequestMappingHandlerMapping.class);
          }
      }
docs: Discovers existing {@link org.springframework.web.servlet.HandlerMapping handler mappings} in the provided
  context. Provides the default mappings (see original dispatcher servlet) in case no mappings
  exist in the context.