let dynamicArray = DynamicArray()

// REACT
dynamicArray.signal ~> { changedValues, change, indexSet in
    println(change)
}

// add object to proxy (NSMutableArray)
dynamicArray.proxy.addObject(123)

// `change = .Insertion` will be printed

let model = MyModel(array: [1])

// pass NSMutableArray so that `ForwardingDynamicArray` can tweak it
let dynamicArray = ForwardingDynamicArray(model.mutableArrayValueForKey("array"))

// REACT
dynamicArray.signal ~> { changedValues, change, indexSet in
    println(change)
}

// add object to proxy (NSMutableArray)
dynamicArray.proxy.addObject(2)

// `change = .Insertion` will be printed & `model.array` will be updated as `[1, 2]`