public function preview($width, $height)
    {
        if (!$width || !$height) {
            throw new \Exception('Please, provide both width and height for preview');
        }
        $result = clone $this;
        $result->operations[]['preview'] = array(
            'width' => $width,
            'height' => $height,
        );
        return $result;
    }
public function preview($width, $height)
    {
        if (!$width || !$height) {
            throw new \Exception('Please, provide both width and height for preview');
        }
        $result = clone $this;
        $result->operations[]['preview'] = array(
            'width' => $width,
            'height' => $height,
        );
        return $result;
    }
public function preview ( $ width , $ height ) { if ( ! $ width || ! $ height ) { throw new \ Exception ( 'Please, provide both width and height for preview' ) ; } $ result = clone $ this ; $ result -> operations [ ] [ 'preview' ] = array ( 'width' => $ width , 'height' => $ height , ) ; return $ result ; }
Get object with preview parameters.
Provide both width and height.
If no width and height are provided exceptions will be thrown!

@param int $width Preview image width.
@param int $height Preview image height.
@throws \Exception
@return File
Get object with preview parameters . Provide both width and height . If no width and height are provided exceptions will be thrown!