One of the most common programming patterns in Ruby is the singleton pattern, which is especially useful when writing in a more functional style. Modulation makes it easier to write singletons by treating source-file as singleton modules by default. Thus, any method defined in such a module is a singleton method. This reduces the boilerplate usually involved in writing Ruby singelton to the bare minimum.

In the present example, the imported module is a singleton implementing the interface expected by the application.