I went through some of the tests. I find those examples hard to use in simple examples. I feel they are geared towards testing out the codebase.
For samples, I'd recommend a new package that have a classes with a main method and help on how to invoke them with different CLI options (e.g: switch between Reflect/Specific/Generic API where appropriate).
The above is a simple example of code that switches between Generic and Specific API. It would be useful if examples such as these lived in package called samples (... or something). They would then be updated with changes to the codebase.
When I write code for my projects I keep examples such as those around in a separate package to help me get my bearings. I find the ability to play with examples very useful when one has to deal with multiple packages.
I spent some time with tests and you are right they were a bit too complicated and also hard to play with i.e. manipulate slightly to see the effects of a small change.
One example to add to the Reflect API would be the inheritance/interfaces to imply unions (my interpretation of what is happening in one of the tests).