Prototype Chain Cycles (#25980)

* Prototype Chain Cycles

* Fix error message

guide/english/javascript/prototypes/index.md

@@ -61,6 +61,24 @@ console.log(obj2.c); // undefined
 
 In above snippet, the statement `var obj2 = Object.create(obj1)` will create `obj2` object with prototype  `obj1` object. In other words, `obj1` becomes the prototype of `obj2` instead of `Object.prototype` by default. As you can see,  `b` is not a property of `obj2`, you can still access it via the  prototype chain. For `c` property, however, you get `undefined` value because it can't be found in `obj1` and `Object.prototype`.
 
+#### Limitations
+
+While setting the prototypes of objects, ensure that the prototype chain does not form a cycle. 
+
+```
+let apple = {};
+let pear = {};
+let carrot = {};
+
+
+Object.setPrototypeOf(apple, pear)
+Object.setPrototypeOf(pear, carrot)
+Object.setPrototypeOf(carrot, apple) // ERROR!
+```
+This wil cause the javascript engine to throw a `TypeError: Cyclic __proto__ value` error.
+
+The reasoning behind this is that the engine does not know which object is more "senior" when passing through the chain.
+
 ### Classes
 
 In ES2016, we now get to use the `Class` keyword as well as the methods mentioned above to manipulate `prototype`. The JavaScript `Class` appeals to developers from OOP backgrounds, but it's essentially doing the same thing as above.