composing objects and make methods and objects testable

upload_example.php

<?php

require_once __DIR__ . '/../vendor/autoload.php';

$uploadHandler = new \Acme\FileUpload\UploadHandler();
$uploadHandler
  ->setFormFieldName('upload')
  ->setTargetDirectory(__DIR__ . '/../uploads')
  ->addValidator(new JpegFileTypeValidator())
  ->addValidator(new maxFileSizeValidator(4096))
  ->addValidator(new fileExistsValidator()); // don't overwrite existing uploads

// ... 

$uploadHandler->handle($_FILES);