traits.js

function _extend(object, source) {
    for (var key in source) {
        if (source.hasOwnProperty(key)) {
            object[key] = source[key];
        }
    }
    return object;
}
 
function _with() {
    var self = {};
    var args = Array.prototype.slice.call(arguments);
    for (var i = 0; i < args.length; i++) {
        args[i](self);
    }
    self.super = _extend({}, self);
    return self;
}