code: def ensure_files(self, filenames):
          
          logger.debug("Testing {0} for the following files: {1}".format(
              self.working_dir, filenames))
          dircontent = os.listdir(self.working_dir)
          for fname in filenames:
              if fname not in dircontent:
                  return False
          return True
docs: Checks the student submission for specific files.
  
          Args:
              filenames (tuple): The list of file names to be cjecked for.
  
          Returns:
              bool: Indicator if all files are found in the student archive.