PhpOffice\PhpPresentation\Slide\AbstractSlide::getExtentX PHP Method

    public function getExtentX()
    {
        if ($this->extentX === null) {
            $extents = GeometryCalculator::calculateExtents($this);
            $this->extentX = $extents[GeometryCalculator::X];
            $this->extentY = $extents[GeometryCalculator::Y];
        }
        return $this->extentX;
    }