// function doSomeWork() {
//   console.log('Doing some work...')
//   console.log('Work done!')
//   return { data: 'some data' }
// }

function doSomeWork(fn) {
  console.log('Doing some work...')

  setTimeout(function() {
    console.log('Work done!')
    fn({ data: 'some data' })
  }, 1000)
}

console.log('Application starting')

doSomeWork(function(value) {
  console.log('Value is', value)
  console.log('Application ending')
})