public @NotNull Set<XmlFile> getConfigFiles(@Nullable C context) {
    if (context == null) {
      return Collections.emptySet();
    }
    final M model = getModel(context);
    if (model == null) {
      return Collections.emptySet();
    }
    else {
      return model.getConfigFiles();
    }
  }
public @NotNull Set<XmlFile> getConfigFiles(@Nullable C context)