docs: def key_exists(self, key, secret=False):
          '''
          Check is given key exists.
  
          :param key: Key ID
          :param secret: Check secret key
          :rtype: bool
          '''
          if len(key) < 8:
              return False
          key = key.upper()
          res = self.list_keys(secret)
          for fingerprint in res.keys:
              if fingerprint.endswith(key):
                  return True
          return False