The only closed reference to `this` in the example is a mutation, in an event handler. This is supposed retain the reference and it’s not even a leak. The simpl

The only closed reference to `this` in the example is a mutation, in an event handler. This is supposed retain the reference and it’s not even a leak. The simplest way to solve that would be to remove the event handler, but even simpler would be to treat `this` as a value type and never change it after construction. The other reference is easily rewritten as a WeakMap key and would not retain a reference, but easier still could be written as a local binding with no reference to `this` at all.