code: private void configureExceptionResolvers() {
          Map<String, HandlerExceptionResolver> resolvers = this.factory.getBeansOfType(HandlerExceptionResolver.class);
          DefaultHandlerExceptionResolver defaultResolver;
  
          if (resolvers.isEmpty()) {
              defineBean(ExceptionHandlerExceptionResolver.class);
              defineBean(ResponseStatusExceptionResolver.class);
              defaultResolver = defineBean(DefaultHandlerExceptionResolver.class);
          } else {
              defaultResolver = getBean(DefaultHandlerExceptionResolver.class).orElse(null);
          }
  
          if (defaultResolver != null) {
              defaultResolver.setWarnLogCategory("mvc");
          }
      }
docs: Discovers existing {@link org.springframework.web.servlet.HandlerExceptionResolver exception resolvers} in the provided
  context. Provides the default resolvers (see original dispatcher servlet) in case no resolvers
  exist in the context.