}
  }

  public void testReplaceFrom() {
    assertThat(is('a').replaceFrom("yaha", 'o')).isEqualTo("yoho");
    assertThat(is('a').replaceFrom("yaha", "")).isEqualTo("yh");
    assertThat(is('a').replaceFrom("yaha", "o")).isEqualTo("yoho");
    assertThat(is('a').replaceFrom("yaha", "oo")).isEqualTo("yoohoo");
    assertThat(is('>').replaceFrom("12 > 5", ">")).isEqualTo("12 > 5");
  }

  public void testRetainFrom() {

  InternetDomainName(String name) {
    // Normalize:
    // * ASCII characters to lowercase
    // * All dot-like characters to '.'
    // * Strip trailing '.'

    name = Ascii.toLowerCase(DOTS_MATCHER.replaceFrom(name, '.'));

    if (name.endsWith(".")) {
      name = name.substring(0, name.length() - 1);
    }

    checkArgument(name.length() <= MAX_LENGTH, "Domain name too long: '%s':", name);
    this.name = name;