PhpBench\Model\Variant::hasErrorStack PHP Method

    public function hasErrorStack()
    {
        return null !== $this->errorStack;
    }

 /**
  * {@inheritdoc}
  */
 public function variantEnd(Variant $variant)
 {
     if ($variant->hasErrorStack()) {
         $this->output->write(sprintf("    %-30s<error>ERROR</error>", $variant->getSubject()->getName()));
         $this->output->write(PHP_EOL);
         return;
     }
     $this->output->write(sprintf("\t%s", $this->formatIterationsFullSummary($variant)));
     $this->output->write(PHP_EOL);
 }