public function testCanUseXvfbRun()
{
$inFile = $this->getHtmlAsset();
$outFile = $this->getOutFile('png');
$binary = $this->getBinary();
$image = new Image(array('binary' => $binary, 'commandOptions' => array('enableXvfb' => true)));
$this->assertInstanceOf('mikehaertl\\wkhtmlto\\Image', $image->setPage($inFile));
$this->assertTrue($image->saveAs($outFile));
$tmpFile = $image->getImageFilename();
$command = (string) $image->getCommand();
$this->assertEquals("xvfb-run --server-args=\"-screen 0, 1024x768x24\" {$binary} '{$inFile}' '{$tmpFile}'", $command);
unlink($outFile);
}