code: def validate_and_copy_one_submission(self, submission_path):
      
      if os.path.exists(self.download_dir):
        shutil.rmtree(self.download_dir)
      os.makedirs(self.download_dir)
      if os.path.exists(self.validate_dir):
        shutil.rmtree(self.validate_dir)
      os.makedirs(self.validate_dir)
      logging.info('\n' + ('#' * 80) + '\n# Processing submission: %s\n'
                   + '#' * 80, submission_path)
      local_path = self.copy_submission_locally(submission_path)
      metadata = self.base_validator.validate_submission(local_path)
      if not metadata:
        logging.error('Submission "%s" is INVALID', submission_path)
        self.stats.add_failure()
        return
      submission_type = metadata['type']
      container_name = metadata['container_gpu']
      logging.info('Submission "%s" is VALID', submission_path)
      self.list_of_containers.add(container_name)
      self.stats.add_success(submission_type)
      if self.do_copy:
        submission_id = '{0:04}'.format(self.cur_submission_idx)
        self.cur_submission_idx += 1
        self.copy_submission_to_destination(submission_path,
                                            TYPE_TO_DIR[submission_type],
                                            submission_id)
        self.id_to_path_mapping[submission_id] = submission_path
docs: Validates one submission and copies it to target directory.
  
      Args:
        submission_path: path in Google Cloud Storage of the submission file