@Bean
    public PluginDataHandler signPluginDataHandler() {
        return new SignPluginDataHandler();
    }
sign plugin data handler.

@return the plugin data handler
shenyu-spring-boot-starter/shenyu-spring-boot-starter-plugin/shenyu-spring-boot-starter-plugin-sign/src/main/java/org/apache/shenyu/springboot/starter/plugin/sign/SignPluginConfiguration.java