list setup output structure sometimes very different

Hi,
not sure if I can explain what I mean properly but: for the list/setup API call I have to write ugly postprocessing code to make sure that the structure of the API output is uniformly. This makes the function difficult to maintain when server changes happen, as I then have to rewrite the ugly postprocessing code. Here some examples:

1. https://test.openml.org/api/v1/json/setup/list/limit/1 (this has only a setup and flow slot)
2. https://test.openml.org/api/v1/json/setup/list/limit/10 (this additionally has parameter slot, which shows the flow.id but not the setup.id, to get the setup.id for each parameter I have to use the parent field)

I think I would be happy if you could only output show the parameter field with the following subfields (see comments) and always make sure that the output has the same structure (i.e. empty fields are shown with a null value or something like this):

<oml:id>53004</oml:id> #  I don't need this
<oml:flow_id>5685</oml:flow_id> # this is nice to have, also setup.id would be great
<oml:setup_id>29337</oml:setup_id> # I added this field manually now
<oml:full_name>mlr.classif.rpart.tuned(6)_openml.normal.kind</oml:full_name>
<oml:parameter_name>openml.normal.kind</oml:parameter_name>
<oml:data_type>discrete</oml:data_type>
<oml:default_value>Inversion</oml:default_value>
<oml:value>Inversion</oml:value>

The difficult maintaining part is that I always have to do if-else conditions to check which structure the API outputs (as I never know this beforehand). So having an API that always makes sure to output an unified structure makes this easier for clients. Do you think you can change this?

Compare the two setup list API responses linked in the issue, especially their setup, flow, and parameter fields. Define the unified response structure from the requested parameter subfields and verify that missing values are represented consistently; done means clients no longer need conditional postprocessing for these response shapes.