example.swift

func initialize() {
  self.layer.actions = [
    "onOrderOut": NSNull(), 
    "sublayers": NSNull(), 
    "contents": NSNull(), 
    "bounds": NSNull()
  ]
}

func changed() {
  CATransaction.begin()
  CATransaction.setDisableActions(true)
  self.textLayer.string = "a"
  self.textLayer.frame = self.layer.bounds
  CATransaction.commit()
}