code: public static ClientFailoverConfig resolveClientFailoverConfig(ClientFailoverConfig clientFailoverConfig) {
          if (clientFailoverConfig == null) {
              clientFailoverConfig = locateAndCreateClientFailoverConfig();
          }
          checkValidAlternative(clientFailoverConfig.getClientConfigs());
          return clientFailoverConfig;
      }
docs: If {@code clientFailoverConfig} passed {@code null}, then loads
  failover configuration using the search logic described in
  {@link HazelcastClient#newHazelcastFailoverClient()} and builds
  {@link ClientFailoverConfig}.
  
  @param clientFailoverConfig provided via {@link HazelcastClient#newHazelcastFailoverClient(ClientFailoverConfig)}
  @return resolvedConfigs
  @throws HazelcastException  if {@code clientFailoverConfig} is {@code null} and no failover configuration is found
  @throws InvalidConfigurationException when given config is not valid