Implements

N = {};
 
var myExtend = function (destination/**, supers */) {
    var supers = Array.prototype.slice.call(arguments, 1);
    var implementations = destination.implementations || [];
 
    var registerInheritance = function (target, source) {
        if (source.constructor !== Object &&
              !_.include(implementations, source)) {
            implementations.push(source);
        }
    };
 
    _.each(supers, function (localSuper) {
        registerInheritance(destination, localSuper);
        _.extend(destination, localSuper);
    });
 
    if (implementations.length > 0) {
        destination.implementations = implementations;
    }
 
    return destination;
};
 
var implements = function (obj, prototype) {
    var doImplements = false;
    var implementationStack = [];
    var getImplementations = function (source) {
        _.each(source.implementations, function (localImplementation) {
            var notIncluded = !_.any(implementationStack, function (i) {
                return _.isEqual(localImplementation, i);
            });
            if (notIncluded) {   
                implementationStack.push(localImplementation);
            }
            if (localImplementation.implementations &&
                  localImplementation.implementations.length > 0) {
                getImplementations(localImplementation);
            }
        });
    };
    getImplementations(obj);
    doImplements = _.any(implementationStack, function (implementation) {
        return implementation.constructor === prototype;
    });
    console.log(implementationStack);
    return doImplements;
};
N.sup = function () {
    return myExtend(this, {
        sup: 'this'
    });
};
N.Base = function () {
    var sup = new N.sup();
    return myExtend(this, sup, {
        base: 'base'
    });
};
 
N.Gadget = function () {
    var base = new N.Base();
    return myExtend(this, base, {
        bla: 'bla'
    });
};
 
N.middleG = function () {
    var base = new N.Base();
    return myExtend(this, base, {
        lala: 'lala'
    });
};
 
N.GadgetInterface = function () {
    return myExtend(this, {
        i: 'interface'
    });
};
 
N.myGadget = function () {
    var i = new N.GadgetInterface();
    var g = new N.Gadget();
    var gm = new N.middleG();
    return myExtend(this, i, g, gm, { foo:'foo' });
};
 
var s = new N.myGadget();
 
console.log(s);
console.log(implements(s, N.sup));
console.log(implements(s, N.Base));
console.log(implements(s, N.Gadget));
console.log(implements(s, N.GadgetInterface));