/**
  * Constructor
  * call base constructors
  * checks if directory is writable and sets the optional obj_id
  * @param integereger obj_id
  * @access	public
  */
 public function __construct()
 {
     define('MAIL_IMPORT_PATH', 'mail');
     parent::__construct();
     $this->mail_path = parent::getPath() . "/" . MAIL_IMPORT_PATH;
     // IF DIRECTORY ISN'T CREATED CREATE IT
     // CALL STTIC TO AVOID OVERWRITE PROBLEMS
     ilFileDataImportMail::_initDirectory();
     $this->__readFiles();
 }