code: def load(cls, path):
          
          auth = cls()
          with open(path) as fd:
              for pubkey in itertools.imap(str.strip, fd):
                  # skip empty lines
                  if not pubkey:
                      continue
                  auth.add(pubkey)
          return auth
docs: load the keys from a path
          
          :param path: the filename (path) in which we find the keys
          :return: