code: def _ParseAccountsData(self, account_data):
      
      if not account_data:
        return {}
      lines = [line for line in account_data.splitlines() if line]
      user_map = {}
      for line in lines:
        if not all(ord(c) < 128 for c in line):
          self.logger.info('SSH key contains non-ascii character: %s.', line)
          continue
        split_line = line.split(':', 1)
        if len(split_line) != 2:
          self.logger.info('SSH key is not a complete entry: %s.', split_line)
          continue
        user, key = split_line
        if self._HasExpired(key):
          self.logger.debug('Expired SSH key for user %s: %s.', user, key)
          continue
        if user not in user_map:
          user_map[user] = []
        user_map[user].append(key)
      logging.debug('User accounts: %s.', user_map)
      return user_map
docs: Parse the SSH key data into a user map.
  
      Args:
        account_data: string, the metadata server SSH key attributes data.
  
      Returns:
        dict, a mapping of the form: {'username': ['sshkey1, 'sshkey2', ...]}.