Alex\BehatLauncher\Behat\RunUnitList::add PHP Method

    public function add(RunUnit $unit)
    {
        $this->units[] = $unit;
        return $this;
    }

 /**
  * Creates run units
  */
 public function createUnits(array $features)
 {
     foreach ($features as $feature) {
         $unit = new RunUnit();
         $unit->setFeature($feature);
         $unit->setRun($this);
         $this->units->add($unit);
     }
 }