增加一个额外的字段用于额外的查询条件

flowable-core/src/main/java/com/lanyuanxiaoyao/flowable/core/model/FlowableInstance.java

@@ -26,6 +26,8 @@ public class FlowableInstance {
   @Builder.Default
   private LocalDateTime updatedTime = LocalDateTime.now();
 
+  private String extra;
+
   public void addMetadata(Map<String, Object> metadata) {
     this.metadata.putAll(metadata);
   }