* parsing fails. Always use this method in preference to {@link #fromValid(String)} for a
   * specifier that is not already known to be valid.
   *
   * @throws ParseException if the specifier is not valid.
   */
  @CanIgnoreReturnValue // TODO(b/219820829): consider removing
  public static HostSpecifier from(String specifier) throws ParseException {
    try {
      return fromValid(specifier);
    } catch (IllegalArgumentException e) {

  }

  private static HostSpecifier spec(String specifier) {
    return HostSpecifier.fromValid(specifier);
  }

  public void testNulls() {
    NullPointerTester tester = new NullPointerTester();

    tester.testAllPublicStaticMethods(HostSpecifier.class);
    tester.testAllPublicInstanceMethods(HostSpecifier.fromValid("google.com"));
  }

  private void assertGood(String spec) throws ParseException {