enemy animations from RW tutorials that are not implemented in production

enemy.swift

// The RW tutorials with game kit show a variety of useful "enemy" functions. Want a simple place to grab from without opening the PDF later.
    func spawnEnemy() {
        
      // basic enemy positioning
        let enemy = SKSpriteNode(imageNamed: "enemy")
        enemy.position = CGPoint(
            x: size.width + enemy.size.width/2,
            y: CGFloat.random(
                min: playableRect.minY + enemy.size.height/2,
                max: playableRect.maxY - enemy.size.height/2))
        enemy.setScale(0.3)
        
      // adding to the scene
        addChild(enemy)
        
        // how the "enemy" appears and disappears
        let actionMove =
            SKAction.moveTo(x: -enemy.size.width/2, duration: 2.0)
        
        let actionRemove = SKAction.removeFromParent()
      // initialization of the movement and removal  
      enemy.run(SKAction.sequence([actionMove, actionRemove]))
        
      
      // this cannot go when the other stuff above is going -- it's a different set of animation. This is for sequenced motion
       let enemy = SKSpriteNode(imageNamed: "enemy")
       enemy.position = CGPoint(x: size.width + enemy.size.width/2, y: size.height/2)
                                addChild(enemy)
       let actionMidMove = SKAction.moveBy(
           x: -size.width/2-enemy.size.width/2,
           y: -playableRect.height/2 + enemy.size.height/2,
           duration: 1.0)
       
       let actionMove = SKAction.moveBy(
           x: -size.width/2-enemy.size.width/2,
           y: playableRect.height/2 - enemy.size.height/2,
           duration: 1.0)
       // 3 make the enemy wait around
       let wait = SKAction.wait(forDuration: 0.25)
       let logMessage = SKAction.run() {
           print("Reached bottom!")
       }
  
       // this cannot go when the above is going from the last marker to here. This reverses the animation.
       let reverseMid = actionMidMove.reversed()
       let reverseMove = actionMove.reversed()
       let sequence = SKAction.sequence([
             actionMidMove, logMessage, wait, actionMove,
             reverseMove, logMessage, wait, reverseMid
              ])

       // this cannot go when the above is gong from the last marker to here. This halves the animation for finer control
       let halfSequence = SKAction.sequence(
           [actionMidMove, logMessage, wait, actionMove])
       let sequence = SKAction.sequence(
           [halfSequence, halfSequence.reversed()])
       

       // 4 THIS MUST GO NO MATTER THE ABOVE TO KEEP THE SEQUENCE IN PLACE
       // Run sequence of enemy forever or just for this one interval(enemy.run)
       let repeatAction = SKAction.repeatForever(sequence)
       enemy.run(repeatAction)
        enemy.run(sequence)
    }