code: protected void initBytes(StringBuilder source) {
  
      if (this.bytes == null) {
        if (this.string != null) {
          String encodingValue = getEncoding();
          try {
            this.bytes = this.string.getBytes(encodingValue);
          } catch (UnsupportedEncodingException e) {
            source.append(".encoding");
            throw new NlsIllegalArgumentException(encodingValue, source.toString(), e);
          }
        } else if (this.hex != null) {
          this.bytes = parseBytes(this.hex, "hex");
        } else {
          throw new XmlInvalidException(
              new NlsParseException(XML_TAG, XML_ATTRIBUTE_HEX + "|" + XML_ATTRIBUTE_STRING, source.toString()));
        }
      }
    }
docs: This method initializes the internal byte array.
  
  @param source describes the source.