public function testDefaultOptionsWithJPG()
 {
     $watermark_jpg = new PDFWatermark($this->_assets_directory . 'star.jpg');
     $watermarker_jpg = new PDFWatermarker($this->_assets_directory . 'test.pdf', $this->output, $watermark_jpg);
     $watermarker_jpg->savePdf();
     $this->assertTrue(file_exists($this->output) === true);
     $this->assertTrue(filesize($this->_assets_directory . 'output-from-jpg.pdf') === filesize($this->output));
 }