class TieredFeatureToggleVersion implements Service {

  /**
   * Generates a welcome message from the passed {@link User}. The resulting message depends on the
   * group of the {@link User}. So if the {@link User} is in the {@link UserGroup#paidGroup} then
   * the enhanced version of the welcome message will be returned where the username is displayed.
   *
   * @param user the {@link User} to generate the welcome message for, different messages are
   *             displayed if the user is in the {@link UserGroup#isPaid(User)} or {@link
   *             UserGroup#freeGroup}
   * @return Resulting welcome message.
   * @see User
   * @see UserGroup
   */
  @Override
  public String getWelcomeMessage(User user) {<FILL_FUNCTION_BODY>}

  /**
   * Method that checks if the welcome message to be returned is the enhanced version. For this
   * instance as the logic is driven by the user group. This method is a little redundant. However
   * can be used to show that there is an enhanced version available.
   *
   * @return Boolean value {@code true} if enhanced.
   */
  @Override
  public boolean isEnhanced() {
    return true;
  }

}

    if (UserGroup.isPaid(user)) {
      return "You're amazing " + user + ". Thanks for paying for this awesome software.";
    }

    return "I suppose you can use this software.";
  
<no_super_class>