function testSaveAsDownloadsFileToTarget()
 {
     \VCR\VCR::turnOn();
     \VCR\VCR::insertCassette('gathercontent_save_file.yml');
     $file_url = 'https://gathercontent.s3.amazonaws.com/filename_hash';
     $target_filename = $this->tempDir() . '/file.jpg';
     $this->assertFileNotExists($target_filename);
     $subject = new Downloader($file_url);
     $subject->saveAs($target_filename);
     $this->assertFileExists($target_filename);
     $this->assertEquals('file-contents', file_get_contents($target_filename));
     \VCR\VCR::eject();
     \VCR\VCR::turnOff();
 }