old_contents: /*
   * Since 1.8 the players skin can have a second layer over their whole skin.
   *
   * This example will toggle that layer every half second, making your skin 'blick'
   * (If your bots skin has a second layer)
   */
  const mineflayer = require('mineflayer')
  
  if (process.argv.length < 4 || process.argv.length > 6) {
    console.log('Usage : node jumper.js <host> <port> [<name>] [<password>]')
    process.exit(1)
  }
  
  const bot = mineflayer.createBot({
    host: process.argv[2],
    port: parseInt(process.argv[3]),
    username: process.argv[4] ? process.argv[4] : 'skin_blinker',
    password: process.argv[5]
  })
  
  var show = true
  
  function toggleSkin () {
    show = !show
    bot.setSettings({
      skinParts: {
        showJacket: show,
        showHat: show,
        showRightPants: show,
        showLeftPants: show,
        showLeftSleeve: show,
        showRightSleeve: show
      }
    })
  }
  
  bot.on('spawn', () => {
    setInterval(() => {
      toggleSkin()
    }, 500)
  })
  
new_contents: /*
   * Since 1.8 the players skin can have a second layer over their whole skin.
   *
   * This example will toggle that layer every half second, making your skin 'blick'
   * (If your bots skin has a second layer)
   */
  const mineflayer = require('mineflayer')
  
  if (process.argv.length < 4 || process.argv.length > 6) {
    console.log('Usage : node jumper.js <host> <port> [<name>] [<password>]')
    process.exit(1)
  }
  
  const bot = mineflayer.createBot({
    host: process.argv[2],
    port: parseInt(process.argv[3]),
    username: process.argv[4] ? process.argv[4] : 'skin_blinker',
    password: process.argv[5]
  })
  
  let show = true
  
  function toggleSkin () {
    show = !show
    bot.setSettings({
      skinParts: {
        showJacket: show,
        showHat: show,
        showRightPants: show,
        showLeftPants: show,
        showLeftSleeve: show,
        showRightSleeve: show
      }
    })
  }
  
  bot.on('spawn', () => {
    setInterval(toggleSkin, 500)
  })
  
subject: Improve skin_blinker example