code: public final void removeRestoreDefaultsListener(
              @NonNull final RestoreDefaultsListener listener) {
          Condition.INSTANCE.ensureNotNull(listener, "The listener may not be null");
          this.restoreDefaultsListeners.remove(listener);
      }
docs: Removes a specific listener, which should not be notified anymore, when the preferences'
  default values should be restored, from the fragment.
  
  @param listener
  The listener, which should be removed as an instance of the type {@link
  RestoreDefaultsListener}. The listener may not be null