The Robert C. Martin Clean Code Collection (Collection)

We had no idea how that would be done because the API had not been designed yet. So we decided to work out the details later.

To keep from being blocked, we defined our own interface. We called it something catchy, like Transmitter.

we are advising you not to pass Maps (or any other interface at a boundary) around your system. If you use a boundary interface like Map, keep it inside the class, or close family of classes, where it is used. Avoid returning it from, or accepting it as an argument to, public APIs.

Not only are learning tests free, they have a positive return on investment. When there are new releases of the third-party package, we run the learning tests to see whether there are behavioral differences.