text: class ZombieManager {
    constructor(game) {
      this.initMembers(game)
      this.initZombies()
      this.initDOMs()
    }
  
    initMembers = game => {
      this.game = game
  
      this.level = 0
      this.zombieCount = 0
  
      this.zombies = new Map()
    }
  
    initZombies = () => {
      this.setupLevel()
    }
  
    initDOMs = () => {
      this.updateDOMS()
    }
  
    update = delta => {
      this.zombies.forEach(zombie => {
        zombie.update(delta)
      })
    }
  
    updateDOMS = () => {
      this.updateLvlDOM()
      this.updateZBDOM()
    }
  
    updateLvlDOM = () => setLvlDOM(this.level)
  
    updateZBDOM = () => {
      setZBDOM(this.zombieCount)
    }
  
    setupLevel = () => {
      this.game.notificationManager.addNotif('Level up!')
  
      this.level++
  
      const count = getZombieCount(this.level)
  
      this.zombies.forEach(zombie => {
        const { x, y } = this.game.world.getRandomSpawner()
        zombie.revive(x, y)
      })
  
      for (let i = this.zombies.size; i < count; i++) {
        const { x, y } = this.game.world.getRandomSpawner()
        const newZombie = new Zombie(this.game, x, y)
  
        this.zombies.set(newZombie.id, newZombie)
      }
  
      this.zombieCount = count
  
      this.updateZBDOM()
      this.updateLvlDOM()
    }
  
    setDead = zombie => {
      this.zombieCount--
      this.updateZBDOM()
  
      if (this.zombieCount <= 0) {
        this.game.regenPodManager.genPod(zombie.x, zombie.y)
        this.setupLevel()
      }
    }
  }
  