FileUpload\FileNameGenerator\Custom::getFileName PHP Method

    public function getFileName($source_name, $type, $tmp_name, $index, $content_range, FileUpload $upload)
    {
        if (is_string($this->generator) && !is_callable($this->generator)) {
            return $this->generator;
        }
        return call_user_func_array($this->generator, func_get_args());
    }

 public function testCallableGenerator()
 {
     function generateName()
     {
         return func_get_arg(0);
     }
     $generator = new Custom("FileUpload\\FileNameGenerator\\generateName");
     $playground_path = __DIR__ . '/../playground';
     $filename = "picture.jpg";
     $server = array('CONTENT_TYPE' => 'image/jpg', 'CONTENT_LENGTH' => 30321);
     $file = array('tmp_name' => $playground_path . '/real-image.jpg', 'name' => 'real-image.jpg', 'size' => 30321, 'type' => 'image/jpg', 'error' => 0);
     $fileUpload = new FileUpload($file, $server, $generator);
     $fileUpload->setFileSystem(new Mock());
     $fileUpload->setPathResolver(new Simple($playground_path . "/uploaded"));
     $new_filename = generateName($filename, "image/jpg", "asdf.jpg", 0, "100", $fileUpload);
     $this->assertEquals($generator->getFileName($filename, "image/jpg", "asdf.jpg", 0, "100", $fileUpload), $new_filename);
 }