List of multiple registrable classes as input

I recently found myself in the need to modify some of my data input at random to make my model more robust. Hence I wrote a number of different mutator classes to experiment with.
My original idea was to register there mutator classes and use them as input to my DataSetReader. This worked fine for a single mutator class. However, I found myself that I would like to combine multiple different Mutator classes with different settings into the DataSetReader.

I found that simple supplying a list of registered classes in my jsonnet did not work so good when using jsonnet.
For example, I tried to use my given mutator class Alpha(p: float, replacement: List[str]) and Beta(p: float). which are inherited from the registerable BaseMutator, and supply those to my DataSetReader(mutator: List[BaseMutator], _andOtherArguments)`. However, while this isn’t a problem in python, I have troubles specifying this in jsonnet.
This seems not to work:

    "dataset_reader": {
        "mutator": [
            "type": "alpha",
            "p": 0.1,
            "replacement": ['something', 'something_more']
            "type": "beta",
            "p": 0.1,

However, maybe my approach is completely wrong. I can imagine that this is a rather common situation so I would really appreciate any suggestions.

Can you give the actual error that you’re seeing? From what I can tell, this should work (and it’s supposed to work; if it doesn’t it’s a bug).

Solved the problem. It does indeed work like how I described it above.
The error I encountered was that it could not find the correct “type”. This was due to a typing error of mine. A bit annoying and I learned my lesson here!