SOURCE

Function.prototype.call = function(context, ...rest) {
    const ctx = context || window;

    ctx.fn = this;

    const result = eval("ctx.fn(...rest)");

    delete ctx.fn;

    return result;
};

const me = { name: 'Jack' }
function say() {
  console.log(`My name is ${this.name || 'default'}`);
}
say.call(me)