The command design pattern in action in C# Finally, the following code snippet illustrates how you can perform a simple calculation using the SimpleCalculator class.

The next class in our design is named “TeamLead,” and it represents the “Composite” type in our design, extends the Employee class, and provides the definition for the abstract methods.

One of the subtleties of software library design is deciding on how many constructors to implement. Too few constructors can hamper using the library, but too many constructors can bloat the library.