code: public static boolean birthdayEquals (@Nullable final LocalDate aDate1, @Nullable final LocalDate aDate2)
    {
      return birthdayCompare (aDate1, aDate2) == 0;
    }
docs: Check if the two birthdays are equal. Equal birthdays are identified by
  equal months and equal days.
  
  @param aDate1
  First date. May be <code>null</code>.
  @param aDate2
  Second date. May be <code>null</code>.
  @return <code>true</code> if month and day are equal