Fix clippy::perf lint errors

src/packages/map_basic.rs

@@ -46,9 +46,7 @@ mod map_functions {
     }
     pub fn fill_with(map1: &mut Map, map2: Map) {
         map2.into_iter().for_each(|(key, value)| {
-            if !map1.contains_key(&key) {
-                map1.insert(key, value);
-            }
+            map1.entry(key).or_insert(value);
         });
     }