def __str__(self) -> str:
    duration_strs = []
    duration_strs.append(f'experiment duration: {self.experiment_duration}')
    duration_strs.append(f'training duration: {self.training_duration}')
    duration_strs.append(f'validation duration: {self.validation_duration}')
    duration_strs.append(f'checkpoint duration: {self.checkpoint_duration}')
    return '\n'.join(duration_strs)
def __str__(self) -> str:
    duration_strs = []
    duration_strs.append(f'experiment duration: {self.experiment_duration}')
    duration_strs.append(f'training duration: {self.training_duration}')
    duration_strs.append(f'validation duration: {self.validation_duration}')
    duration_strs.append(f'checkpoint duration: {self.checkpoint_duration}')
    return '\n'.join(duration_strs)