byte[] getByteBodyContents() {
   if (bytePayload != null) {
     return bytePayload;
   }
   final String body = (payload == null) ? bodyParams.asFormUrlEncodedString() : payload;
   try {
     return body.getBytes(getCharset());
   } catch (UnsupportedEncodingException uee) {
     throw new OAuthException("Unsupported Charset: " + getCharset(), uee);
   }
 }