Using a constructor to rebind "this" in classes, solving the problem of https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes#binding_this_with_prototype_and_static_methods

index.js

class MyClass {
    constructor() {
        const self = this;
        Object.getOwnPropertyNames( MyClass.prototype )
            .filter(name => name.indexOf('_') === 0)
            .filter(name => typeof self[name] === 'function')
            .forEach(function(name) {
                self[name.substr(1)] = function() {
                    self[name].apply(self, arguments);
                }
            });
    }

    name = 'Aidan';

    _hello() {
        console.log(`Hello ${this.name}`);
    }
}

let instance = new MyClass();
instance.hello();
instance._hello();
let f = instance.hello;
f();
let f2 = instance._hello;
f2();