}

  private static void checkFromStringCase(
      String hpString,
      int defaultPort,
      @Nullable String expectHost,
      int expectPort,
      boolean expectHasExplicitPort) {
    HostAndPort hp;
    try {
      hp = HostAndPort.fromString(hpString);
    } catch (IllegalArgumentException e) {
      // Make sure we expected this.
      assertNull(expectHost);