Generate random grammar expansions in TatSu (Python)

I'm writing an interpreter for a grammar parser generated with TatSu. I'm looking for a convenient way to generate use cases for my grammar, so I can write unit tests for my interpreter. Currently, I'm generating my test cases by hand.

I wonder if the TatSu package does provide any (maybe undocumented) means to auto-generate random grammar productions so I could use them as test cases for my interpreter. In addition, it would be desirable to specify the grammar rule, for which I need the random productions.