code: @Nullable
    public Date getDateOfBirthEnd() {
      if (birthDayEnd == null || birthMonthEnd == null || birthYearEnd == null) {
        return null;
      }
  
      GregorianCalendar calendar = new GregorianCalendar(birthYearEnd, birthMonthEnd, birthDayEnd);
      return calendar.getTime();
    }
docs: Returns the end of the date of birth range.
  
  @return the end of the date of birth range, may be null