public function setPositionObjectInteractions(PositionObjectInteractionCollection $positionObjectInteractions)
    {
        if (count($positionObjectInteractions) > 0) {
            $this->positionObjectInteractions = $positionObjectInteractions;
        } else {
            $msg = "A PositionObjectStage object must be composed of at least 1 PositionObjectInteraction object, none given.";
            throw new InvalidArgumentException($msg);
        }
    }
public function setPositionObjectInteractions(PositionObjectInteractionCollection $positionObjectInteractions)
    {
        if (count($positionObjectInteractions) > 0) {
            $this->positionObjectInteractions = $positionObjectInteractions;
        } else {
            $msg = "A PositionObjectStage object must be composed of at least 1 PositionObjectInteraction object, none given.";
            throw new InvalidArgumentException($msg);
        }
    }
public function setPositionObjectInteractions ( PositionObjectInteractionCollection $ positionObjectInteractions ) { if ( count ( $ positionObjectInteractions ) > 0 ) { $ this -> positionObjectInteractions = $ positionObjectInteractions ; } else { $ msg = "A PositionObjectStage object must be composed of at least 1 PositionObjectInteraction object, none given." ; throw new InvalidArgumentException ( $ msg ) ; } }
Set the positionObjectInteractions composing the positionObjectStage.

@param \qtism\data\content\interactions\PositionObjectInteractionCollection $positionObjectInteractions A collection of PositionObjectInteraction objects.
@throws \InvalidArgumentException If $positionObjectInteractions is empty.
Set the positionObjectInteractions composing the positionObjectStage .