@java.lang.Override
    public long getRequestId() {
        return requestId_;
    }
<pre>
Response =&gt; [4, 9]
"request_id" is used to tell the client that
this notification is a response to the specific request
</pre>

<code>optional int64 request_id = 4;</code>

@return The requestId.
turms-server-common/src/main/java/im/turms/server/common/access/client/dto/notification/TurmsNotification.java