diff --git a/src/main/java/com/github/hcsp/objectbasic/Main.java b/src/main/java/com/github/hcsp/objectbasic/Main.java
index 31b5c3a..04e2fda 100644
--- a/src/main/java/com/github/hcsp/objectbasic/Main.java
+++ b/src/main/java/com/github/hcsp/objectbasic/Main.java
@@ -5,7 +5,8 @@
 public class Main {
     public static void main(String[] args) {
         // 请修复这里的编译错误，令实际调用的方法是print(HashMap)
-        print(null);
+        HashMap map = new HashMap();
+        print(map);
     }
 
     public static void print(int i) {