<T extends JpsElement, P, K extends JpsElementChildRole<T> &JpsElementParameterizedCreator<T, P>>
  T getOrSetChild(@NotNull K role, @NotNull Supplier<P> param);
<T extends JpsElement, P, K extends JpsElementChildRole<T> &JpsElementParameterizedCreator<T, P>>
  T getOrSetChild(@NotNull K role, @NotNull Supplier<P> param)