homework: extract print_status into a separate trait

smart-house/src/house.rs

@@ -1,4 +1,4 @@
-use crate::{Device, Error, Room};
+use crate::{Device, Error, PrintStatus, Room};
 use std::collections::HashMap;
 
 #[derive(Debug)]
@@ -36,8 +36,10 @@ impl House {
         };
         Ok(device)
     }
+}
 
-    pub fn print_status(&self) {
+impl PrintStatus for House {
+    fn print_status(&self) {
         for (room_name, room) in self.rooms.iter() {
             println!("{}:", room_name);
             println!("{}", "-".repeat(32));