feat(timed): add func cost fn

note.md

@@ -4601,4 +4601,31 @@ onBeforeUnmount(() => {
 
 ---
 
-## 164.
+## 164. calc func runing cost time
+
+```js
+function timed(f) {
+  return function (...args) {
+    console.log(`Entering function ${f.name}`);
+    let startTime = Date.now();
+    try {
+      return f(...args); 
+    } finally {
+      console.log(`Exiting ${f.name} after
+${Date.now() - startTime}ms`);
+    }
+  };
+}
+
+function benchmark(n) {
+  let sum = 0;
+  for(let i = 1; i <= n; i++) sum += i; 
+
+  return sum;
+}
+
+timed(benchmark)(1000000);
+```
+
+---
+