diff --git a/src/main/java/com/monkeyk/sos/web/context/SOSContextHolder.java b/src/main/java/com/monkeyk/sos/web/context/SOSContextHolder.java
index ac03ebe..2e32ca1 100644
--- a/src/main/java/com/monkeyk/sos/web/context/SOSContextHolder.java
+++ b/src/main/java/com/monkeyk/sos/web/context/SOSContextHolder.java
@@ -19,6 +19,9 @@ import org.springframework.util.Assert;
 public class SOSContextHolder implements BeanFactoryAware, InitializingBean {
 
 
+    /**
+     * @since 2.1.0
+     */
     private static BeanFactory beanFactory;