Itérateurs : SYMBOL

const m = 'myMethod';
class Foo {
    [m]() {}
}

Donc, on pourra écrire : 

class IterableClass {
    [Symbol.iterator]() {
        ···
    }
}

Several special methods in ECMAScript 6 have keys that are symbols. Computed method names allow you to define such methods. For example, if an object has a method whose key is Symbol.iterator, it is iterable. That means that its contents can be iterated over by the for-of loop and other language mechanisms.

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