code: public ByteBuffer append(String str) {
          if (str != null)
              return append(DocWriter.getISOBytes(str));
          return this;
      }
docs: Appends a <CODE>String</CODE> to the buffer. The <CODE>String</CODE> is
  converted according to the encoding ISO-8859-1.
  @param str the <CODE>String</CODE> to be appended
  @return a reference to this <CODE>ByteBuffer</CODE> object