feat GroupMessageEvent: add setMsgSeq method

Author: Kloping

src/main/java/io/github/kloping/qqbot/api/v2/GroupMessageEvent.java

@@ -1,17 +1,26 @@
 package io.github.kloping.qqbot.api.v2;
 
+import io.github.kloping.qqbot.api.SenderV2;
 import io.github.kloping.qqbot.api.message.MessageEvent;
 import io.github.kloping.qqbot.entities.qqpd.v2.Contact;
 import io.github.kloping.qqbot.entities.qqpd.v2.Group;
 
 /**
  * @author github.kloping
  */
-public interface GroupMessageEvent extends GroupEvent, MessageEvent<Contact,Group>, MessageV2Event {
+public interface GroupMessageEvent extends GroupEvent, MessageEvent<Contact,Group>, MessageV2Event, SenderV2 {
     /**
      * 发送环境
      *
      * @return
      */
     Group getSubject();
+
+
+    /**
+     * 设置消息序列号并返回原序列号
+     * @param seq
+     * @return
+     */
+    Integer setMsgSeq(Integer seq);
 }

src/main/java/io/github/kloping/qqbot/impl/message/v2/BaseGroupMessageEvent.java

@@ -124,6 +124,13 @@ public Integer getMsgSeq() {
         return seq++;
     }
 
+    @Override
+    public Integer setMsgSeq(Integer seq) {
+        Integer oseq = this.seq;
+        this.seq = seq;
+        return oseq;
+    }
+
     @Override
     public String toString() {
         return String.format("[type(%s) %s].%s:%s"