• As the RepositoryClient defines an abstract base class, the methods do not have an implementation and instead serves as a base for other derived classes. If we are dealing with Git service APIs that return data structures different from what the abstract methods in RepositoryClient specify, it’s the responsibility of the derived class to handle it properly. When implementing the abstract methods, the derived class should process the data returned by the API and format it to match the requirements.

• It is possible to implement some default behavior in the RepositoryClient. However, the purpose of using an abstract base class is to define a common interface for its subclasses. Adding default behavior in the base class might not make sense in all usage scenarios and can add unnecessary complexity. If there are common operations that are shared across all the subclasses, it might be beneficial to define a utility module or class where all these common functionalities can be placed. Alternatively, we can have a base class that implements these common methods and have other classes inherit from this base class.