Revise function need additional data from Simon

[vumichien]

This PR revise the test case need additional data

[terryyz]

Thanks @vumichien! Would you mind updating the corresponding samples in data/raw and remove those test data folders? BTW, could you please also remove some examples from each sample and keep 1-2 at most? Just don't want to make models rely on the docstring examples too mcuh, as they are greatly aligned with some test cases.