message: use scoped lifetime to tear down nodes before shutdown in test_Frame
diff: @@ -25,6 +25,7 @@ int main(int argc, const char *argv[])
  {
  ospInit(&argc, argv);
  + {
  std::cout << "Rendering a test frame..." << std::endl;
  auto frame_ptr = createNodeAs<Frame>("frame", "Frame", "test frame");
  @@ -43,8 +44,8 @@ int main(int argc, const char *argv[])
  frame.unmapFrame(pixels);
  std::cout << "\nresult saved to 'test_Frame.ppm'" << std::endl;
  + }
  - frame_ptr.reset();
  ospShutdown();
  return 0;
  