how can i add a shader to a SceneKit object in swift 2.0

i have a SceneKit game with only SceneKit geometry objects written in Swift 1.2 (started this in may)

its runs perfect so far

then i started looking around for info on adding a shader to my scene to spice it up a bit and found that apple has a pretty big library of shaders

so i changed the shader i liked to what i needed and added it to my objects

since development will not be ready by next week (im not sure if apple will release a GM seed then or not, but i want to play safe) i need to make my game ready for swift 2.0

after running the migration assistent to migrate from swift 1.2 to 2.0 my entire app broke

linker command errors and al that nasty stuff

so i started to migrate manually

but how can i add shaders to a scene in swift 2.0 ?

thanks

here is my code i used to add it in 1.2 (this works in v1.2, but gve me an error in 2.0)

let shaders = NSMutableDictionary()

shaders[SCNShaderModifierEntryPointFragment] = String(contentsOfFile: NSBundle.mainBundle().pathForResource("wallShader", ofType: "shader")!, encoding: NSUTF8StringEncoding, error: nil)

var material = SCNMaterial()

material.shaderModifiers = shaders as [NSObject : AnyObject]

var wallNode = SCNNode(geometry: geo)

wallNode.geometry!.materials = [material]