Simple Example is Incomplete or Unclear - CounterReducerImpl

[ZonZonZon]

In an abstract class CounterReducer it is not clear where does CounterReducerImpl appear from:

public static CounterReducer create() { return new CounterReducerImpl(); // Note: usage of generated class }

The same about builder():

Reducer<Todo> todoReducer = TodoReducer.builder() .itemsReducer(new ItemsReducer()) .searchQueryReducer(new QueryReducer()) .build();

Thank you.

[ZonZonZon]

Should have enabled annotations processing in Android Studio Settings and add its entries into build.gradle.