对嵌套函数运行单元测试

I come from the Java world, where you can hide variables and functions and then run unit tests against them using reflection. I have used nested functions to hide implementation details of my classes so that only the public API is visible. I am trying to write unit tests against these nested functions to make sure that I don't break them as I develop. I have tried calling one of the nested functions like:I come from the Java world, where you can hide