@Nullable
  @Override
  public Ref<PyType> getReturnType(@NotNull PyCallable callable, @NotNull TypeEvalContext context) {
    final PsiElement pythonStub = PyiUtil.getPythonStub(callable);
    if (pythonStub instanceof PyCallable) {
      final PyType type = context.getReturnType((PyCallable)pythonStub);
      if (type != null) {
        return Ref.create(type);
      }
    }
    return null;
  }
@Nullable
  @Override
  public Ref<PyType> getReturnType(@NotNull PyCallable callable, @NotNull TypeEvalContext context)