feat: support dataset update

[jaycee-li]

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Fixes #1178 🦕

[sasha-gitg]

This line is superfluous. dataset will only exist on assignment after ImageDataset.create is successful.

The test should start with dataset=None

[jaycee-li]

If the ImageDataset.create is successful, then we want to delete the dataset finally. But if create() fails, dataset is None and we shouldn't call dataset.delete(). So I think it's necessary to add this line.

[sasha-gitg]

If create fails then dataset is not defined and if dataset is not None will throw a NameError. dataset isn't created until after the right side of the statement, dataset = aiplatform.ImageDataset.create() is successful. You can validate this behavior in Python:

def f():
    raise RuntimeError('')
    
try:
    dataset = f()
except:
    if dataset is None:
        pass

[jaycee-li]

Got it!

But I see other system tests like test_create_and_import_image_dataset and test_create_tabular_dataset have the same pattern that checks if dataset is not None. Is there any reason for that?

[sasha-gitg]

No, those should be eventually fixed as well.

[jaycee-li]

Got it. Just removed this line. Thank you!