JS-classes with multiple inheritance, super method and more

example.js

var ExampleClass = utils.Class(function(con, struc, tor) {
    this.super([], [struc]);

    this.con = con;
    this.tor = tor;
}, [events.EventEmitter, OtherClass], {
    print: function() {
        return this.con + this.tor;
    } 
});

utils.js

var utils = module.exports = {
    Class: function(c, extending, methods) {
        var D = function() {
            if(!(this instanceof D)) {
                var E = function(args) { D.apply(this, args); };
                E.prototype = D.prototype;
                return new E(arguments);
            }

            c.apply(this, arguments);
        };
        if(!methods) {
            D.prototype = extending;
        } else {
            D.prototype = {
                super: function() {
                    if(Object.prototype.toString.call(extending) === "[object Array]") {
                        for(var i = 0; i < extending.length; ++i) {
                            extending[i].apply(this, arguments[i]);
                        }
                    } else {
                        extending.apply(this, arguments);
                    }
                    this.super = undefined;
                }
            };

            if(Object.prototype.toString.call(extending) === "[object Array]") {
                var proto = {};
                for(var i = 0; i < extending.length; ++i) {
                    utils.Mixin(proto, extending[i].prototype);
                }
                D.prototype.__proto__ = proto;
            } else {
                D.prototype.__proto__ = extending.prototype;                
            }


            for(var m in methods) {
                if(methods.hasOwnProperty(m) && !D.prototype.hasOwnProperty(m)) {
                    D.prototype[m] = methods[m];
                }
            }
        }
        return D;
    },

    Mixin: function(mix, ins) {
        if(ins) {
            for(var m in ins) {
                if(ins.hasOwnProperty(m)) {
                    mix[m] = ins[m];
                }
            }
        }
        return mix;
    },
};