code: def __get_untitled_file_name(self):
          
  
          untitledNameId = Editor._Editor__untitled_name_id
          for file in self.list_files():
              if not os.path.dirname(file) == self.__default_session_directory:
                  continue
  
              search = re.search(r"\d+", os.path.basename(file))
              if not search:
                  continue
  
              untitledNameId = max(int(search.group(0)), untitledNameId) + 1
  
          name = "{0} {1}.{2}".format(self.__default_file_name, untitledNameId, self.__default_file_extension)
          Editor._Editor__untitled_name_id += 1
          LOGGER.debug("> Next untitled file name: '{0}'.".format(name))
          return name
docs: Returns an untitled file name.
  
          :return: Untitled file name.
          :rtype: unicode