[add] code

test_src/arithmetic.cjs

@@ -1,4 +1,10 @@
 module.exports.sum = function sum(a, b) {
+    let x = 0;
+    
+    for(var c in [1,2,3,4]){
+        x+=c;
+    }
+
     return a + b;
 }
 module.exports.div = function div(a, b) {