apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/spi/configuration/AuthConfiguration.java/OidcAuthAutoConfiguration/defaultSsoHeartbeatHandler
class OidcAuthAutoConfiguration:    @Bean
    @ConditionalOnMissingBean(SsoHeartbeatHandler.class)
    public SsoHeartbeatHandler defaultSsoHeartbeatHandler() {
      return new DefaultSsoHeartbeatHandler();
    }