'@param report_progress: Function that is called with a % progress
(number between 0 and 100) for various tasks
If it is called with -1 that means that the
task does not have any progress information'

def set_progress_reporter(self, report_progress):

    if self.verbose:
        logger().info(('%s.set_progress_reporter()' % self.__class__.__name__))
    self.report_progress = report_progress
