* @param mixed could be an html file path or an array with paths example: /var/www/myfile.html or array('/myfile.html','myotherfile.html') or even an indexed array with both 'title' and 'path' indexes for each element like array(0=>array('title'=>'Hello','path'=>'file.html'),1=>array('title'=>'Bye','path'=>'file2.html'));
* @param string pdf name
* @param string course code (if you are using html that are located in the document tool you must provide this)
* @return
* @return void
*/
public function html_to_pdf($html_file_array, $pdf_name = '', $course_code = null, $print_title = false) {