### Environment

* Dubbo version: 3.0.6
* Operating System version: windows10
* Java version: jdk1.8

### Steps to reproduce this issue

String loadbalance() default ClusterRules.EMPTY;



/**
     * Callback method name when connected, default value is empty string
     */
    String onconnect() default "";
    /**
     * Callback method name when disconnected, default value is empty string
     */
    String ondisconnect() default "";
    /**
     * Service owner, default value is empty string
     */
    String owner() default "";
    /**
     * Service layer, default value is empty string
     */
    String layer() default "";
    /**
     * Service invocation retry times
     *
     * @see org.apache.dubbo.common.constants.CommonConstants#DEFAULT_RETRIES
     */
    int retries() default -1;
    /**
     * Load balance strategy, legal values include: random, roundrobin, leastactive
     *
     * you can use {@link org.apache.dubbo.common.constants.LoadbalanceRules#RANDOM} ……
     */
    String loadbalance() default ClusterRules.EMPTY;
    /**
     * Whether to enable async invocation, default value is false