/** Creates the right data object for given primary file. * It is guaranteed that the provided file is realy primary file * returned from the method findPrimaryFile. * * @param primaryFile the primary file * @return the data object for this file * @exception DataObjectExistsException if the primary file already has data object */ protected MultiDataObject createMultiObject (FileObject primaryFile) throws DataObjectExistsException { return new XMLDataObject (primaryFile, this); }