How to reference SKSpriteNode without full instantiation in Swift3? - swift

Question

Previously, I had been using var progressBar = ProgressBar?() right above init within one of my SKSpriteNode subclasses, to allow various methods to reference progressBar throughout the class like so:
class Ship:SKSpriteNode{
var progressBar = ProgressBar?()
static var shipState = "norm"
var powerupOn = false
var moveSpeed:CGFloat
var lives:Int
var canShoot = false
let las = SKSpriteNode(texture:laserTexture)
var gun:GenericGun = GenericGun()
let scaleFactor:CGFloat = 0.07
init(startPosition startPos:CGPoint, controllerVector:CGVector){
self.lives = 3
self.moveSpeed = 160
super.init(texture: ship0, color: UIColor.clear, size: ship0.size())
//Set position
self.position = startPos
attachGun(gun)
self.setScale(scaleFactor)
self.physicsBody = SKPhysicsBody(texture: self.texture!, size: self.size)
self.physicsBody?.isDynamic = true
self.physicsBody?.categoryBitMask = PhysicsCategory.Ship
self.physicsBody?.collisionBitMask = 0
self.physicsBody?.contactTestBitMask = PhysicsCategory.Alien
self.physicsBody?.allowsRotation = false
self.physicsBody?.angularVelocity = CGFloat(0)
self.physicsBody?.usesPreciseCollisionDetection = true
self.physicsBody?.affectedByGravity = false //TBD
self.physicsBody?.velocity.dx = controllerVector.dx * moveSpeed
self.physicsBody?.velocity.dy = controllerVector.dy * moveSpeed
self.name = "ship"
//Call animations
self.animateShip1()
}
func updateVelocity(_ v:CGVector){
self.physicsBody?.velocity.dx = v.dx * moveSpeed
self.physicsBody?.velocity.dy = v.dy * moveSpeed
}
func attachGun(_ gun:GenericGun){
gun.position = CGPoint(x: 0, y: 0)
self.addChild(gun)
}
func animateShip1() {
let animate = SKAction.animate(with: shipFrames, timePerFrame: 0.1)
let forever = SKAction.repeatForever(animate)
self.run(forever)
}
func updateShipProperties(shipVelocity v:CGVector,laserStartPos laserStart:CGPoint){
updateVelocity(v)
progressBar?.position = CGPoint(x: self.position.x - (self.size.width/2 + self.size.width/7.0), y: self.position.y)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
In Swift3 I'm getting an error that I need to provide full arguments, is there a way to achieve this same functionality in Swift3?