MarshalOutputStream objOut = new MarshalOutputStream (out);
//Write message header
if (returnValue instanceof Throwable) {
log.log (Level.FINER, "Exceptional return");
objOut.writeByte (TransportConstants.ExceptionalReturn);
//If the exception is a RemoteException, wrap it in a RemoteException
if (!(returnValue instanceof RemoteException)) {
log.log (Level.FINEST, "Wrapping exception in RemoteException");
returnValue = new RemoteException ("An error occured while processing the Computable object", (Throwable)returnValue);