🔧 use existing relative-indexing-method example

_data/stage3.yml

@@ -243,25 +243,11 @@
     A proposal to add a <code>.at()</code> method to all the basic indexable
     classes (<code>Array</code>, <code>String</code>, <code>TypedArray</code>).
   example: |-
-    function at(n) {
-    &#x9;// ToInteger() abstract op
-    &#x9;n = Math.trunc(n) || 0;
-    &#x9;// Allow negative indexing from the end
-    &#x9;if(n &#x3C; 0) n += this.length;
-    &#x9;// OOB access is guaranteed to return undefined
-    &#x9;if(n &#x3C; 0 || n &#x3E;= this.length) return undefined;
-    &#x9;// Otherwise, this is just normal property access
-    &#x9;return this[n];
-    }
-
-    // Other TypedArray constructors omitted for brevity.
-    for (let C of [Array, String, Uint8Array]) {
-        Object.defineProperty(C.prototype, &#x22;at&#x22;,
-                              { value: at,
-                                writable: true,
-                                enumerable: false,
-                                configurable: true });
-    }
+    var list = [&#x22;apple&#x22;, &#x22;orange&#x22;, &#x22;banana&#x22;];
+    list.at(-1) // banana, using negative index
+    list.at(0)  // apple
+    list.at(1)  // orange
+    list.at(2)  // banana
   has_specification: true
   presented:
     - date: "November\_2020"