String ancestorName = name.substring(substringFrom);

    return new InternetDomainName(ancestorName, ancestorParts);
  }

  /**
   * Creates and returns a new {@code InternetDomainName} by prepending the argument and a dot to
   * the current name. For example, {@code InternetDomainName.from("foo.com").child("www.bar")}
   * returns a new {@code InternetDomainName} with the value {@code www.bar.foo.com}. Only lenient

    assertEquals("com", InternetDomainName.from("google.com").parent().toString());
    assertEquals("uk", InternetDomainName.from("co.uk").parent().toString());
    assertEquals("google.com", InternetDomainName.from("www.google.com").parent().toString());

    assertThrows(IllegalStateException.class, () -> InternetDomainName.from("com").parent());
  }

  public void testChild() {
    InternetDomainName domain = InternetDomainName.from("foo.com");