public function createResult($benchmark = null, $extraCmd = '')
{
$benchmark = $benchmark ?: 'benchmarks/set4';
$process = $this->phpbench('run ' . $benchmark . ' --executor=debug --dump-file=' . $this->fname . ' ' . $extraCmd);
if ($process->getExitCode() !== 0) {
throw new \Exception('Could not generate test data:' . $process->getErrorOutput() . $process->getOutput());
}
$document = new Document();
$document->load($this->fname);
return $document;
}