[TIMOB-25807] Hyperloop - ES6: Cannot find scoped "this" methods anymore

    var ButtonDelegate = Hyperloop.defineClass('ButtonDelegate', 'NSObject');

    ButtonDelegate.addMethod({
        selector: 'buttonPressed:',
        instance: true,
        arguments: ['UIButton'],
        callback: (sender) => { 
            if (this.buttonPressed) {
//              ^-- Here is the issue - it cannot find the declared method
                this.buttonPressed(sender);
            }
        }
    });

    var delegate = new ButtonDelegate();

    // Not found when being used in "Hyperloop.addMethod"
    delegate.buttonPressed = function(sender) {
        alert('Button pressed!');
    };