def set_diff(self, file_diff):
        """ set_diff: records progress from getting file diff
            Args: file_diff ([str]): list of files that don't exist on Kolibri Studio
            Returns: None
        """
        self.file_diff = file_diff
        self.__record_progress(Status.START_UPLOAD)
set_diff: records progress from getting file diff
            Args: file_diff ([str]): list of files that don't exist on Kolibri Studio
            Returns: None