old_contents: var app = require('app')
  var BrowserWindow = require('browser-window')
  
  var createWindow = function () {
    return new BrowserWindow({
      width: 800,
      height: 600,
      show: true
    })
  }
  
  app.on('ready', createWindow)
  
new_contents: #!/usr/bin/env atom-shell
  
  var app = require('app')
  var BrowserWindow = require('browser-window')
  
  var createWindow = function () {
    return new BrowserWindow({
      width: 800,
      height: 600,
      show: true
    })
  }
  
  app.on('ready', createWindow)
  
subject: add shebang