completed test part

exercises/16_lifetimes/lifetimes3.rs

@@ -8,7 +8,7 @@ struct Book<'a> {
 
 // Will the strings pointed to by book still be valid?
 fn main() {
-    let book = Book {
+    // let book = Book {
         author: "George Orwell",
         title: "1984",
     };