objectSerializerExample.swift

    public static func ObjectMapperSerializer<T: Mappable>(keyPath: String?, mapToObject object: T? = nil, context: MapContext? = nil) -> ResponseSerializer<T, NSError> {
        return ResponseSerializer { request, response, data, error in
            guard error == nil else {
                return .Failure(error!)
            }
            
            guard let _ = data else {
                let failureReason = "Data could not be serialized. Input data was nil."
                let error = newError(.DataSerializationFailed, failureReason: failureReason)
                return .Failure(error)
            }
            
            let JSONResponseSerializer = Request.JSONResponseSerializer(options: .AllowFragments)
            let result = JSONResponseSerializer.serializeResponse(request, response, data, error)
        
            let JSONToMap: AnyObject?
            if let keyPath = keyPath where keyPath.isEmpty == false {
                JSONToMap = result.value?.valueForKeyPath(keyPath)
            } else {
                JSONToMap = result.value
            }
            
            if let object = object {
                Mapper<T>().map(JSONToMap, toObject: object)
                return .Success(object)
            } else if let parsedObject = Mapper<T>(context: context).map(JSONToMap){
                return .Success(parsedObject)
            }

            let failureReason = "ObjectMapper failed to serialize response."
            let error = newError(.DataSerializationFailed, failureReason: failureReason)
            return .Failure(error)
        }
    }