*
   * Here are some examples:
   *
   * ```java
   * assertEquals("google.com", getEffectiveTldPlusOne("google.com"));
   * assertEquals("google.com", getEffectiveTldPlusOne("www.google.com"));
   * assertNull(getEffectiveTldPlusOne("com"));
   * assertNull(getEffectiveTldPlusOne("localhost"));
   * assertNull(getEffectiveTldPlusOne("mymacbook"));
   * ```
   *