code: private static boolean fieldExistsInSkeleton(int field, String skeleton)
      {
          String fieldChar = DateIntervalInfo.CALENDAR_FIELD_TO_PATTERN_LETTER[field];
          return ( (skeleton.indexOf(fieldChar) == -1) ? false : true ) ;
      }
docs: /*
  check whether a calendar field present in a skeleton.
  @param field      calendar field need to check
  @param skeleton   given skeleton on which to check the calendar field
  @return           true if field present in a skeleton.