protected function renderBehaviourParallax()
    {
        if ( ! in_array( self::BEHAVIOUR_PARALLAX, $this->behaviours )) {
            return '';
        }

        $parallaxOptions = $this->parallaxOptions;
        $parallaxTag     = ArrayHelper::remove( $parallaxOptions, 'tag', 'div' );

        ArrayHelper::remove( $parallaxOptions, self::PARALLAX_BACKGROUND );
        ArrayHelper::remove( $parallaxOptions, self::PARALLAX_TRANSITION );
        ArrayHelper::remove( $parallaxOptions, self::PARALLAX_TRANSITION_X );
        ArrayHelper::remove( $parallaxOptions, self::PARALLAX_TRANSITION_Y );
        ArrayHelper::remove( $parallaxOptions, self::PARALLAX_DURATION );

        return Html::tag( $parallaxTag, '', $parallaxOptions );
    }