The create method takes a subset of the properties needed to create a new mission. The remaining values are provided by the method itself. This allows factories to simplify the process of creating similar instances. In the main function, you can see that two Mars missions have been created, only differing in name and Rocket instance. We've halved the number of values needed to create an instance.
This pattern can help reduce instantiation logic. In this recipe, we simplified the creation of different kinds of missions by identifying the common attributes, encapsulating those in the body of the factory function, and using arguments to supply the remaining properties. In this way, commonly used instance shapes can be created ...
