copying class in CoffeeScript

copy.coffee

copyClass = (klass) ->
    newKlass = (new Function("""
        return function (call) {
            return function #{klass.name}() {
                return call(this, arguments)
            };
        };
    """)())(Function.apply.bind(klass))

    for own key, value of klass
        newKlass[key] = value

    F = ->
    F.prototype = klass.prototype
    newKlass.prototype = new F()

    return newKlass

see

https://github.com/shinout/copy-class