title: Getting undefined function public_path() error in lumen
body: <p>I am trying to upload image in lumen. I got some examples and when i tried to implement it, got below error
  <code>&lt;!-- Call to undefined function App\Http\Controllers\public_path() (500 Internal Server Error) --&gt;</code></p>
  <p>Just want to confirm is this function got changed or do i need to include helper file.</p>
  <p>Thanks</p>