code: public void replace(int start, int limit, String text) {
          buf.replace(start, limit, text);
      }
docs: Replace zero or more characters with new characters.
  <code>Replaceable</code> API.
  @param start the beginning index, inclusive; <code>0 &lt;= start
  &lt;= limit</code>.
  @param limit the ending index, exclusive; <code>start &lt;= limit
  &lt;= length()</code>.
  @param text new text to replace characters <code>start</code> to
  <code>limit - 1</code>