public function crop($xoffset, $yoffset, $width, $height)
    {
        if ($xoffset === null) {
            throw new \LogicException('"xoffset" must not be null for "crop"');
        }

        if ($yoffset === null) {
            throw new \LogicException('"yoffset" must not be null for "crop"');
        }

        if ($width === null) {
            throw new \LogicException('"width" must not be null for "crop"');
        }

        if ($height === null) {
            throw new \LogicException('"height" must not be null for "crop"');
        }

        $this->image->crop($width, $height, $xoffset, $yoffset);
    }