Modules that contain abstract binding methods (@Binds, @Multibinds) or only static @Provides methods will not be instantiated by Dagger when they are included in a component. Adding a private constructor clearly conveys that the module will not be used as an instance.
Suppress false positives by adding the suppression annotation @SuppressWarnings("PrivateConstructorForNoninstantiableModule") to the enclosing element.