core-bundle/src/Resources/contao/library/Contao/Image.php
public function setZoomLevel($zoomLevel)
	{
		$zoomLevel = (int) $zoomLevel;

		if ($zoomLevel < 0 || $zoomLevel > 100)
		{
			throw new \InvalidArgumentException('Zoom level must be between 0 and 100!');
		}

		$this->zoomLevel = $zoomLevel;

		return $this;
	}
public function setZoomLevel($zoomLevel)
	{
		$zoomLevel = (int) $zoomLevel;

		if ($zoomLevel < 0 || $zoomLevel > 100)
		{
			throw new \InvalidArgumentException('Zoom level must be between 0 and 100!');
		}

		$this->zoomLevel = $zoomLevel;

		return $this;
	}
Set the zoom level

@param integer $zoomLevel The zoom level

@return $this The object instance

@throws \InvalidArgumentException If the zoom level is out of bounds