Spring Why in ConfigurationClassPostProcessor.processConfigBeanDefinitions need if (registry.getBeanDefinitionCount() > candidateNames.length) {} judge

@Import({SimpleStart.MemberClass.class})
public class SimpleStart {

    public SimpleStart(ExampleBean exampleBean) {

    }


    static class MemberClass implements ImportBeanDefinitionRegistrar {
        private Environment environment;

        public MemberClass(Environment environment) {
            this.environment = environment;
        }

        @Override
        public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
            if(environment.getProperty("new-config.enable", Boolean.class,false)){
                registry.removeBeanDefinition("oldBeanConfig");
                registry.registerBeanDefinition(NewBeanConfig.class.getName(), BeanDefinitionBuilder.genericBeanDefinition(NewBeanConfig.class).getBeanDefinition());
            }
        }
    }

}

public class NewBeanConfig {
    @Bean
    ExampleBean exampleBean(){
        return new ExampleBean();
    }
}

public class OldBeanConfig{

}

public class ExampleBean {

}

@Test
public void research(){
     System.setProperty("new-config.enable","true");
    AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(SimpleStart.class,OldBeanConfig.class);
    ExampleBean bean = context.getBean(ExampleBean.class);

}

The above code will cause the ExampleBean to not be obtained,When I saw ConfigurationClassPostProcessor source code,I found processConfigBeanDefinitions method have if (registry.getBeanDefinitionCount() > candidateNames.length) {} lead to no more process NewBeanConfig ConfigClass.I don't see why did it.

Comment From: snicoll

SimpleSart is not annotated with @Configuration. This turns what is called "the lite mode" where only basic methods are checked. NewBeanConfig should also be flagged with @Configuration.

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