code: private void append(StringBuffer result, String string,
                          FieldDelegate delegate,
                          FieldPosition[] positions,
                          Format.Field signAttribute) {
          int start = result.length();
  
          if (string.length() > 0) {
              result.append(string);
              for (int counter = 0, max = positions.length; counter < max;
                   counter++) {
                  FieldPosition fp = positions[counter];
                  Format.Field attribute = fp.getFieldAttribute();
  
                  if (attribute == Field.SIGN) {
                      attribute = signAttribute;
                  }
                  delegate.formatted(attribute, attribute,
                                     start + fp.getBeginIndex(),
                                     start + fp.getEndIndex(), result);
              }
          }
      }
docs: Appends the String <code>string</code> to <code>result</code>.
  <code>delegate</code> is notified of all  the
  <code>FieldPosition</code>s in <code>positions</code>.
  <p>
  If one of the <code>FieldPosition</code>s in <code>positions</code>
  identifies a <code>SIGN</code> attribute, it is mapped to
  <code>signAttribute</code>. This is used
  to map the <code>SIGN</code> attribute to the <code>EXPONENT</code>
  attribute as necessary.
  <p>
  This is used by <code>subformat</code> to add the prefix/suffix.