Case 1: metrics on a single dataset
    >>> # add the following lines in your config
    >>> # 1. use `EditValLoop` instead of `ValLoop` in MMEngine
    >>> val_cfg = dict(type='EditValLoop')
    >>> # 2. specific EditEvaluator instead of Evaluator in MMEngine
    >>> val_evaluator = dict(
    >>>     type='EditEvaluator',
    >>>     metrics=[
    >>>         dict(type='PSNR', crop_border=2, prefix='Set5'),
    >>>         dict(type='SSIM', crop_border=2, prefix='Set5'),
    >>>     ])
    >>> # 3. define dataloader
    >>> val_dataloader = dict(...)
    Case 2: different metrics on different datasets
    >>> # add the following lines in your config
    >>> # 1. use `EditValLoop` instead of `ValLoop` in MMEngine
    >>> val_cfg = dict(type='EditValLoop')
    >>> # 2. specific a list EditEvaluator
    >>> # do not forget to add prefix for each metric group
    >>> div2k_evaluator = dict(
    >>>     type='EditEvaluator',
    >>>     metrics=dict(type='SSIM', crop_border=2, prefix='DIV2K'))
    >>> set5_evaluator = dict(
    >>>     type='EditEvaluator',
    >>>     metrics=[
    >>>         dict(type='PSNR', crop_border=2, prefix='Set5'),
    >>>         dict(type='SSIM', crop_border=2, prefix='Set5'),
    >>>     ])
    >>> # define evaluator config
    >>> val_evaluator = [div2k_evaluator, set5_evaluator]
    >>> # 3. specific a list dataloader for each metric groups
    >>> div2k_dataloader = dict(...)
    >>> set5_dataloader = dict(...)
    >>> # define dataloader config
    >>> val_dataloader = [div2k_dataloader, set5_dataloader]

# Example for `split`
gen_sample = EditDataSample()
gen_sample.fake_img = outputs  # tensor
gen_sample.noise = noise  # tensor
gen_sample.sample_kwargs = deepcopy(sample_kwargs)  # dict
gen_sample.sample_model = sample_model  # string
# set allow_nonseq_value as True to copy non-sequential data (sample_kwargs and sample_model for this example)
batch_sample_list = gen_sample.split(allow_nonseq_value=True)  
# Example for `stack`
data_sample1 = EditDataSample()
data_sample1.set_gt_label(1)
data_sample1.set_tensor_data({'img': torch.randn(3, 4, 5)})
data_sample1.set_data({'mode': 'a'})
data_sample1.set_metainfo({
    'channel_order': 'rgb',
    'color_flag': 'color'
})
data_sample2 = EditDataSample()
data_sample2.set_gt_label(2)
data_sample2.set_tensor_data({'img': torch.randn(3, 4, 5)})
data_sample2.set_data({'mode': 'b'})
data_sample2.set_metainfo({
    'channel_order': 'rgb',
    'color_flag': 'color'
})
data_sample_merged = EditDataSample.stack([data_sample1, data_sample2])