Javascript ES6 retrieve members of class

The idea is to get the list of methods/properties of class. For example, I have this class:

// foo.js
class FooController {
    constructor() {
    }
    *bar(next) {
        yield next;
        return 'meh';
    },
    meh() {
        return 'bar';
    }
}
module.exports = FooController;

Now I want to retrieve the member of FooController. This should be done easily for javascript plain object, but not with class:

// index.js
var Foo = require('foo');
var foo = new Foo();

// inspect
console.log(foo); // expected: { bar, meh }, but got {}

// struggle with lodash
var _ = require('lodash');    
console.log(_.keys(foo)); // expected ['bar', 'meh'], but got []

Any idea? Thanks in advance for any help or suggestions.