Mocking

Mocking refers to the practice of writing simulated resources to enable unit testing. Sometimes, the words "fake" or "stub" are used. For example, a middleware system that responds with JSON structures from a database would "mock" the database backend for its unit tests. Otherwise, the unit tests would require the database backend to be online, probably also requiring exclusive access. This wouldn't be convenient.

Mockito is a mocking framework for Java that has also been ported to Python.