`this` is not pointing at instance of called class

this is not bound in created and destroyed, so it's hard to access custom context variables:

export class TestComponent extends Rete.Component {
  constructor(foo) {
    super("Test");
    this.foo = foo;
  }
  created(node) {
    console.log(`Created ${node.id} for ${this.foo}`); // Won't work, because `this` will be `undefined`
  }
}

The function hooks should be bound to the respective class instance.

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Background

In my particular use-case, I'd like to have a context variable (equivalent to foo) point at a container DOM element and each node owns a DOM child that is attached to the container DOM element. However, during node creation / destruction I'm unable to find the container DOM element, because this is undefined.