code: protected String subFormat(char ch, int count, int beginOffset,
                                 FieldPosition pos, DateFormatSymbols fmtData,
                                 Calendar cal)
          throws IllegalArgumentException
      {
          // Note: formatData is ignored
          return subFormat(ch, count, beginOffset, 0, DisplayContext.CAPITALIZATION_NONE, pos, cal);
      }
docs: Formats a single field, given its pattern character.  Subclasses may
  override this method in order to modify or add formatting
  capabilities.
  @param ch the pattern character
  @param count the number of times ch is repeated in the pattern
  @param beginOffset the offset of the output string at the start of
  this field; used to set pos when appropriate
  @param pos receives the position of a field, when appropriate
  @param fmtData the symbols for this formatter