*
   * @return {@code true} if this domain name appears exactly on the public suffix list
   * @since 6.0
   */
  public boolean isPublicSuffix() {
    return publicSuffixIndex() == 0;
  }

  /**
   * Indicates whether this domain name ends in a {@linkplain #isPublicSuffix() public suffix},
   * including if it is a public suffix itself. For example, returns {@code true} for {@code

      assertFalse(name, domain.isPublicSuffix());
      assertTrue(name, domain.hasPublicSuffix());
      assertTrue(name, domain.isUnderPublicSuffix());
    }
  }

  public void testUnderPublicSuffix() {
    for (String name : SOMEWHERE_UNDER_PS) {
      InternetDomainName domain = InternetDomainName.from(name);
      assertFalse(name, domain.isPublicSuffix());
      assertTrue(name, domain.hasPublicSuffix());

      assertFalse(name, domain.isPublicSuffix());
      assertTrue(name, domain.hasPublicSuffix());
      assertTrue(name, domain.isUnderPublicSuffix());
    }
  }

  public void testUnderPublicSuffix() {
    for (String name : SOMEWHERE_UNDER_PS) {
      InternetDomainName domain = InternetDomainName.from(name);
      assertFalse(name, domain.isPublicSuffix());
      assertTrue(name, domain.hasPublicSuffix());