Call at regular intervals within long running tasks to add pause breakpoints.
        :return: time that the task was paused for, always 0.0 if it didn't pause
        :rtype: float

def check_pause(self):
        """
        Call at regular intervals within long running tasks to add pause breakpoints.
        :return: time that the task was paused for, always 0.0 if it didn't pause
        :rtype: float
        """

        # todo task_runner vs model

        pause_time = 0.0
        sleep_time = 0.1
        if self.model.tasks_paused:
            while self.model.tasks_paused:
                sleep(pause_time)
                pause_time += sleep_time
        return pause_time